Nah, I think I'm ok.
My hardware is plenty fast enough to run the latest MAME.
My MAME cab is a Pentium M overclocked to 2.7GHz with 1GB of memory.
I did a bunch of benchmarking and my setup beats a 2.8GHz AMD Athlon 64 FX-57 in almost every game.
My problem with the latest versions of MAME is that there are far too many core changes happening and it's just not stable yet. Combine that with all the changes for the hi-res artwork support, and the recent video and sound changes, and the change that broke triple buffering, and you see where I'm going with this.
I have no doubt that eventually it will all settle down, but I want the new games on my cab now and I don't have any major complaints about MAME 106 so I was hoping someone out there had used that as a base and backported the updated drivers and CPU cores from newer MAME versions.