Can I 'Play' Games?
If by 'playing' a game, you mean: at full speed with sound, perfect graphics, etc, then NO. Come back next year.
Since this release (PCSX2 0.8) compatibility has increased greatly. Many games will now go 'in-game' or atleast to some form of menu. Whilst games may get 'in-game', they will not run at 'playable' speeds, due to the complex nature of PS2 emulation, and the lack of modern hardware that is powerfull enough to emulate such a console.
Some games that are known to be going 'in-game'.
Beats of Rage v1.0028 [SLPS 66666] (PD - Senile Team)
Bust A Block [SLES 51713] (E)
Capcom VS. SNK 2 [PBPX 95201] (J)
Disgaea - Hour of Darkness [SLUS 20666] (U)
King of Fighters - Maximun Impact [SLUS 20923] (U)
Marvel vs Capcom 2 [SLPM 62227] (J)
Police 24-7 [SLES 50285] (E)
Pool Master [SLES 50052] (E)
Sega Ages 2500 Volume 6 - Bonanza Bros [SLPM 62433] (J)
Sega Ages 2500 Volume 7 - Columns [SLPM 62425] (J)
Sega Ages 2500 Volume 8 - Virtua Racing - Flat Out [SLPM 62443] (J)
SNK vs Capcom - SVC Chaos [SLES 53065] (E)
Street Fighter EX3 [SLUS 20130] (J)
Suikoden III [SLUS 20387] (U)
Super Bust a Move [PBPX 95201] (U)
WTA Tennis Tour USA [SLPM 62046] (J)
Is game 'X' Working?
Don't ask, if it's not already posted, then proberbly not. Go test it yourself. Is game 'X' working in a beta? Same answer, the beta-testing team have a vast collection of games, and post shots when something shows progress or works, so if we haven't posted shots, it's not working.