IMHO, there is nothing wrong with hanging on to the A2 for now.
First of all there are no guarantees that the format will really take hold over BlueRay. Or for that matter, that either of the HD formats are going to succeed.
Secondly, as with everything else, what you bought yesterday, will by outdated tomorrow. The advantages of buying the higher end players will be overshadowed quickly by those the next generation of players.
As far as Elmo on DVD-HD; probably not. But the A2's upscaling will at least make Elmo look fuzzier.