...And when I say emulator, I mean emulator, not what people often think they mean when they mention Aranym, which isn't one.
Hatari in CVS now has the beginnings of support for TT and Falcon emulation - no software that could emulate these machines successfully has ever been released or even publically mentioned before as far as I know.
Unfortunately, Hatari is only developed for Unix systems and the source doesn't seem very easily portable to Windows as yet (okay, I haven't looked at the source, but I'm guessing that that's the case). However, it compiles and runs just fine in Ubuntu and performs well. What a bombshell!
Here's the announcement on the great atari-forum.com site.