Well, it happened. Tonight while playing Fable II, my 360 froze and upon restart, the "E 74 System Error" screen appeared. Unlike last week when I encountered it, repeated attempts to disconnect, let sit, then reconnect have proven futile. I put in an online service request and expect to receive the shipping box from MS by Wednesday.
I guess I'll be out of commission in the league for the next few weeks. Sucks ass because I wanted to use this week to finish up Fable II, so I ccould dedicate the next few weeks to Left 4 Dead. If I knew today would be the end, I at least would've spent last weekend trying to knock out the 5-day and 7-day survivor achievements in Dead Rising. I'm not looking forward to leaving my "incoming" 360 on 15 hours or however long it is needed for those achievements.