Version 2.6.0 Release (Hackmons!)
2.6.0 brings a big addition to PO in the form of Hackmons. Hackmons is a tier created by (I think) Smogon, which allows a Pokémon to use any move, any ability, and more than 510 total EVs (e.g. 252 in every stat). They'll be a thread that explains Hackmons properly soon. Obviously it's going to a play a lot differently to standard tiers, so it'll be interesting to see how it ends up.
In other things, Alice/Cirno has added all the trainer sprites from Gen 1-3, giving a total of 719 trainer sprites from all generations. Also the ability to add any number of battle_fields to a theme has been added. Simply drop the files you want to use in the battle_fields folder and as long as they're in PNG format, the battle window will pick them up. When you select a Mega Evolution in the Teambuilder, it now automatically gives you the Megastone needed (unless you're playing hackmons).
Fixes in terms of the client have been the annoying bug with advanced search I know a fair few people had, fixes to the tooltip in the battle window, and fixes to the way colour selection works.
There's probably things I've forgotten, so check here: http://pokemon-online.eu/forums/solved-bugs.33/ Everything here should be fixed this release.