Well your sig says 5x67, so I'm guessing you just hit 70. I think the groups that are successful with all out DPS in heroics are pretty well geared. Until you reach that level, you might want to consider dropping one of your guys and bringing along a tank friend. I just tried this last night for my first heroic (Slave Pens) and it went pretty well. We only wiped 4 times or so, mostly to just plain bad pulls. Only once to something that was really multiboxing related when I changed my healing macro without testing it and it had a syntax error.
Oh, and don't drop your enchanter like I did!