I agree it's not necessarily a *bad* thing for individual users if WP7 doesn't go down the specs arms race, but with the market leaders (Android & iOS) actively involved in that game and the tech press well aware of it, MS will have to do quite a sell job to overcome the additional handicap of seeming under-specced.
Will people just leap at the chance to buy the Nokia name? I dunno. Their stuff hasn't been big here in almost a decade, since literally before the RAZR (enough time for Moto to get huge, suck, huge again, and start sucking again) -- do people still miss their old colorful dumbphones? How many people even remember them? (Actually, I remember my old StarTac, but that's another story.)
I don't think specs are a big deal. iPhone 4 was outdated almost from day 1. The Thunderbolt, Charge, and Incredible 2 have all been selling like hotcakes, and most of the WP7 Mango phones will be slightly better than them spec-wise.
As for Nokia, the reason their smartphones have flopped so bad in the USA is a) because they only sell them unlocked and b) Symbian. Heck, the only place I have ever seen an N8 in the US was a non-working display model at Fry's, on a display separate from all the other smartphones and from the phone salespeople.
Nokia have said that they're taking a very US-centric approach with their WP7 phones. They're going to sell exclusive models for each carrier, subsidized. They supposedly have a huge ad blitz planned, as well as incentive programs to reward salespeople for selling Nokia phones. (Hopefully, when people see Nokia product placement in movies like Tron Legacy and Transformers 3, they will say "hey that's the phone I saw at the AT&T kiosk", not "WTF is that thing?)
Anyway, I still think Nokia can do a lot of good for WP7 in the US. None of the other OEMS have much incentive to push WP7. They're perfectly happy selling Android phones and avoiding the $15/device license. Nokia, on the other hand, will be putting WP7 on all their flagship models and making some real effort to promote it.