Zx-81 has, as expected released an update for PSPMSX v1.5.1. The MSX Emulator. Just like his other emulators zx-81 has applied IRDA Joystick box support to PSPMSX.
Develpoer notes / Changelog:

For those who have never heard about IRDA joystick project, the goal was to connect your old DB9 joystick (compatible with Atari , Amiga, Amstrad etc [...]

Yoshihiro is back after yesterdays beta 1 release with another update. This time with new added options to get the best out of the Nintendo DS PSP emulator. What’s new:

DSONPSP v0.2C Beta changelog:
* Added setting:
o Screen Vertical needed for some games [...]

Well this is interesting fancy a bit of DS gaming on your PSP? Its something the Nintendo DS fanboy’s out there won’t be a bit happy about. Yoshihiro has released DSONPSP a Nintendo DS emulator for your PSP. Its based on DeSmuME and while in its beta stage is quite slow and suffers from low [...]

Back again the DaedalusX64 Team, with the help of homebrew developer Kreationz have released another update. This time focusing on more improvements to the emulators code and bug fixes. DaedalusX64 just keeps getting better, just check the above video clip and you can see Mario 64 is quite playable and that’s with sound emulation enabled.
DaedalusX64 [...]

The Yabase Team responcable for PC, MAC and other system versions of their Yabase Sega Saturn Emulator have finally released a PSP port for use to try out.
Notes:
Important notice
—————-
PSP support for Yabause is experimental; please be aware that some things
may not work well (or at all), and in particular there’s no configuration
interface yet.
Also, please note [...]

Zx-81 is back from a short break, releasing an update for PSPHugo. His PC Engine / TurboGrafx 16 PSP Emulator. This latest release includes IRDA joystick device support for both the DB9 Joystick and Atari Paddle. Plus there is a menu for the IRDA joystick settings and key mappings. Good work zx-81!
Version 1.3.1 changelog:
[...]

The DaedalusX64 team have released an update to DaedalusX64 The N64 / Nintendo 64 emulator for PSP. This release Alpha Revision 427 adds a few more bug fixes to the list. Also note the developers notes on upgrading your old DaedalusX64 installation.
Developers note:
Upgrade Procedure: Grab the link and unzip it. Delete all *.hle files(in SaveGames) [...]

The JPCSP team have posted another new update to their PC java PSP Emulator. The changelog below lists the changes made in JPCSP v0.3 Revision 1121.
JPCSP v0.3 Revision 1121 changelog:

r1116 Implemented sceIoRemove and sceIoChstat
r1118 First draft implementation for sceKernelRotateThreadReadyQueue
r1119 Fixed compilation problem due to non-UTF-8 character
r1120 Fix for “Tenchu: TOTA”
r1121 Fix for “Unbound Saga – [...]

The JPCSP Team have published another update for their Java PC PSP Emulator. More changes as listed below:
JPCSP v0.3 Revision 1114 Changelog:

r1114 Fixed again Spot light cutoff (thanks to Raziel for providing info).
r1113 Fixed decoding of Vertex Info: this should fix a lot of 3D rendering problems
r1112 Fixed IndexOutOfBoundsException introduced in r1111

Source: [...]

PCE for PSP v0.81 has been released. PCE for PSP is TurboGrafx-16 / PC Engine emulator. made by an unkown Japanese coder. This latest release increases the programs stability and fixes some bugs.
Via: EmuCR

The last recent release a few days ago had a couple of bugs present, so to fix the known errors the JPCSP team have released a quick update fixing this. The changelog below shows what was fixed:
JPCSP v0.3 Revision 1107 Changelog:

r1107 – Avoid lot of “Using Compiler” log messages when exiting Jpcsp
[...]

The JPCSP team are back with another version of there Java PSP emulator for the PC. This version is over 50% fast than version 0.2 and includes many more bugs+fixes as listed below.
JPCSP v0.3 Revision 1105 Changelog.

A huge improvement in CPU/FPU/VFPU added and fixed a considerable instructions which make things better.
v0.3 is 50% faster than [...]

Another small update to the Java PSP Emulator. This latest build has updated findings in VfpuState, Plus a small fix in VCMOVT, VCMOVF and VHDP.
Changelog:
Uploaded REV 1098
Log last changes rev1096-1098
Quote:
r1098 Added more tests in VfpuTest. Updated findings in VfpuState: only small fix in VCMOVT & VCMOVF, VHDP confirmed.
r1097 Renamed SWB into VWB (to match prxtool) [...]

PSP Developer Takka has released another update to to his famous unofficial UO gpsp kai GBA Emulator for PSP. We hope Takka continues to tweak and improve the best Gameboy Advance emulator out there. Not many changes in this latest version. added a zoom feature and fixed the file extractino from zips.
UO gpsp kai 3.4 [...]

The JPCSP Team – creators of the PC Based Java PSP Emulator have released an update. This latest build has added basic GE capture support and more bug fixes.
JPCSP v0.2 Revision 1078 changelog:

Added basic GE capture support, tested on cube sample.
Until we record persistent GE state (texture on/off, etc) for best results
replay captures in the [...]

Been a while, but two recent revisions of DaedalusX64 N64 Emulator have been released by the Daedalus X64 team. This release introduces a number of tweaks and bug fixes.
DaedalusX64 Alpha Revision 407 changelog:
*Fixed GBI1_BranchZ, GBI2_BranchZ uCode commands (Fixes Crash on Pokemon Snap on Phat)
DaedalusX64 Alpha Revision 406
[~]Cleaned up some warnings
[!]Reduced ROM Buffer on Slim [...]

PSP Developer Takka has today released an up to to his famous unofficial UO gpsp kai GBA Emulator for PSP. While his release blog is in Japanese we have gathered the following from the changelog.
* Changed the main font and subfont
* Added missing GBA folder in [...]

PSPHUGO received an update too, as Zx-81 has released version 1.3.0 of his PC Engine / TurboGrafx 16 Emulator. PSPHUGO is a PSP port of the famous Hu-Go emulator.
Changelog:

Audio Track support for CD-ROM (support only MP3 format with stereo 16 bits samples at 22k or 44k rate)
CD-ROM TOC file format support.
Using TurboRip, ripped CD can [...]