The main benefit about the 68010 was the addition of virtual memory instructions. Its fully pin compatible but it's still a 16/32 bit processor so you can't run OS 3.9 on it.
There was some hacks with the A500 running faster than 7 MHz, but on the A500 the cpu speed and floppy speed are very tightly integrated so you couldn't use the drive.
Dunno if the A2000 has the same thing.
You'd be better off with a dual processor board for 68000 cpus. Phillips once made a arbitter for it. Realy nice deal, 'cos the lack of caches makes it much easier to achieve data flow coherency. Just don't know if there was any one who bothered to make such a board for the Amiga. 8-)
