I originally thought of doing 4 pally as dps, and 1 shammy as healer, but I eventually came to the conclusion that cleave in heroics would be my worst nightmare. Besides, there are many things that are simply impossible to do with only melee. If one would be willing to skip alot of stuff, I'm sure it would be pretty cool to go ie 4 warrirors + shammy or something like that. Heck, even 5 warriors would be kickass...just run around and charge/intercept stuff =)

Edit: Actually thinking about it, a setup with shammy+warriors and shammy as main would be quite effective, due to charges and intercept. Intriguing...