Yah, but be careful with voltage levels. Connecting to a full voltage RS232 is going to fry the fpga instantly. You'll need level translation (even for a 5V TTL  port). The serial protocol is customised too (and fixed at 4800 baud to work with a minimalist opto-isolator circuit), so its not just plug and play here. Then again if you're buying an fpga development/educational board you should expect to have to put some effort in

Oh, and to repeat, its only 5MHash/sec, or 2.34MHash/sec or whatever. Just a toy which will mine you some dust only.

[Edit] Clarifcation, by "you" I mean "you dear reader", not "you razorfishl" as you're clearly far more knowledgeable than me!!