i cant figure out how folks seem to think that a special extension is needed for accessing webpages specially designed for mobile devices. This is more about the underlying technology, the page markup and similar stuff all of which do not require a special TLD to be used. Also, the strength of internet (as in network based) technologies comes from the fact it can be accessed by heterogeneous devices like PCs, handhelds etc with different OSs without the need to alter in any way the end users perception of the technology being used for accomplishing the distribution of data. There is NO need for a .mobi TLD for an end user any more than there was a need for a .BLOG TLD for distinguishing certain types of websites that were quite different from the others......
This move can only be of benefit to domain traders and land grabbers and no one else... for end users, it can only add to the confusion. All these new TLDs are making the case for .COM even stronger than it was when there were just a handful of TLDs were around...
an interesting article by tim berners lee :
http://www.w3.org/DesignIssues/TLD