http://www.mame.net/downmain.htmlMAME 0.81 has been released, and it supports 4841 ROM sets, 2728 unique games. 
Here is the whatsnew.txt of 0.81: 
0.81
General Source Changes
----------------------
Various ZN related updates [smf, R.Belmont]
   several games now display more, for example primrag2 plays the intro movie
i386 CPU core (used by the SPI driver) [Ville Linde]
ST-V Improvements [Mariusz Wojcieszek]
   gfx in colmns97 / sassisu / ejihon are improved
CHDMan CHDCD creation fix [R.Belmont]
Improved timing of several 68k instructions [Sebastien VOLPE]
   these changes could do with being verified on a real 68k
   m68kcpu.h, m68kcpu.c:
   ---------------------
   A) scc (68000 only): CYC_SCC_R_FALSE was defined, not used, and misnamed as
      the extra 2 cycles happens when CC is true: now used and renamed to
      CYC_SCC_R_TRUE
   m68kmake.c:
   -----------
   B) add/adda/and/or/sub/suba (68000 only): the 'extra 2 cycles' cases were not
      handled correctly: corrected to be effective on .l only, and also on register
      direct (previously, all sizes were affected, and only in immediate mode)
   C) jmp d(An,Xn) / pea (An) (68000/68010): tables corrected
   D) movem (68000/68010): generated basecount were incorrect in many cases, so I
      added a dedicated table
   m68k_in.c:
   ----------
   E) movem.l d(PC),reglist / movem.l d(PC,Xn),reglist (68000/68010): changed
      basecount
   F) asr/asl/lsr/lsl/ror/rol/roxr/roxl (68000/68010): added '+2n' cycles where
      missing, as the shift/rotate memory is the only case where '+2n' does not
      apply, and is treated in a specific opcode handler.
Fixed small v60 bug related to Aaron's recent changes [Olivier Galibert]
Fixed several small Hyperstone CPU core bugs [Pierpaolo Prazzoli, Mooglyguy]
Fixed a couple of compile warnings for other compilers [Lawrence Gold]
New Games supported or promoted from GAME_NOT_WORKING status:
-------------------------------------------------------------
Gallop Racer [smf]
Beastorizer [R.Belmont, smf]
   both of these have very bad sound emulation
New Non-Working games / clones supported
----------------------------------------
Seibu SPI System (+ related hardware) [Ville Linde]
   gfx are encrypted, sound communication not understood, help on this is welcome.
   Senkyu / Battle Balls
   Viper Phase 1
   E-Jan High School
   Raiden Fighters
   Raiden Fighters 2
D-Day (Jaleco) [Pierpaolo Prazzoli]
   unemulated Jaleco protection chip