Fragmentation has always been one of the feature of Linux (one can call it diversity if we look the other way).
IMHO its one of the problems that doesn't help it to get the market penetration.(but i'm not saying its always a disadvantage).

maemo,moblin,LiMo,ALP,meego,tizen are only a few of the famous Linux efforts in such a nascent state.

Lets face it,we have a not so large but good community for all the major mobile distributions,if we were to work together for a universal standard,we'd have an unbeatable OS already.
Unfortunately this isn't utopia and we have to move on.