My Nokia N900 will load up an almost usable version of Daggerfall with DosBox and it's an 600Mhz ARM.
And that was a game that came out in the era where they were still managing to make DOS games, that also had a 'Windows' version as well.
I haven't tried much else on it. But the real thing I think that would slow it down would be converting VGA to AGA or something, though I'm assuming anyone attempting DosBox has some sort of graphics card?
I would love to play around with this, alas I only have a stock 040 in my A4000D. Anyone offering an 060 for a price that won't make me poor? I have a barely used soul for trade.