Many have suggested that Nokia (and RIM) switch to Android to: a) reduce development and R&D costs/overhead and b) become more competitive "instantly." Nokia has several times said it won't do such a thing; it now has two (count 'em) operating systems: symbian and MeeGo.
A Financial Times interview with Anssi Vanjoki, the departing chief of Nokia’s smartphone division, said that hardware OEMs who've adopted Android (e.g., Motorola, Samsung) are like "Finnish boys who'pee in their pants' for warmth in the winter. Temporary relief is followed by an even worse predicament."
As the piece points out financial firms such as UBS have argued -- just as they did with Yahoo adopting Microsoft search -- that "Nokia could cut annual R&D spending by about €1bn a year if it stopped working on software, lifting the division’s operating margin by 400 basis points."
Vanjoki argued that while there would be some immediate gains, along the lines suggested, in the long term adopting Android would be destructive of Nokia. Adopting Android, he argued, would turn Nokia into "a commoditised box-maker like Dell, scrapping for market share with rivals that all use Android and so seem more or less the same."
This is the predicament that HTC, Motorola and Samsung now find themselves in. It's very challenging to differentiate their phones, although some are more distinctive than others. Because of the "commodity box maker" predicament, I would expect all of them to try and "diverisfy" with Windows Mobile if it's any good.
While Nokia is theoretically correct in its Android analysis, it's uncertain that the Finnish company can deliver a best-in-class smartphone experience on its own software; that's the X variable. For that reason, Nokia might want to do a small test and develop an Android device as merely one among several handset lines -- just in case.