I'd say it's more about long term profitability, but if Microsoft really wants to build a console for the MASS mass market, they can't depend on someone buying their console also buying 6-7 games over the lifetime of the system in order to actually get to the black.
Therefore Microsoft offered more and more services through XBox Live to broaden the income stream.
I mean, can you imagine if the Wii hardware lost Nintendo money for the first 3 years? Sure, they sold a lot of them, but they'd be taking heavily losses instead of massive profits and since I doubt most seniors played anything other than Wii Sports, Nintendo would have been royally screwed.
Well, Nintendo has always made money with the Wii hardware and I doubt they really changed that for the Wii-U. Anyway, after the GC failure and fire sale they weren't even in the position to risk to loose too much money on the Wii experiment.
Interesting that the Wii-U shows that betting on a gimmick to sell your machine is a strategy which can easily fail too.
What is clear is that the overly complicated $500-600 console is dead. I expect both consoles to launch at $399 for the high-end SKU.
Well, mostly like last generation XBox prices. The higher Elite release price back then had probably more to do with clearing stock of old hardware revisions and market situation than a strategic price decision.