I agree that Dell is certainly not a sexy name for gaming systems, for lots of reasons. But I don't think putting AMD's inside Dell boxes helps them there. The AlienWare acquisition does, but no respectable gamer I can imagine would buy a Dell just because you have very little control over the make of the internal boards, which often end up being refurbished crap. High-end gamers want all new boards, all new memory. An AMD chip isn't going to solve that.
The server market is a more promising opening, but the conventional wisdom of Dell's customer service declining (mostly through off-shoring) is not going to fill an IT manager with warm fuzzies.
Not that I'm super-expert-man on this or anything. It's not like I manage an IT department or anything (though I do help with IT functions at my company), and it's possible that this will really help Dell, but I try to keep current on IT sites like SlashDot and Dell's reputation there is not good and it has nothing to do with their failure to offer AMD.