Ignoring the first parts of your post (as I'm not involved in that conversation), if one phone can do a, b, and c but another phone can only do a and b, is it worth buying the second phone if it can do a and b better than the first one? Comparing features across the board isn't always the best way to compare.
As for Pandora on WP7, it is an open API and so you can download one of the many apps on the marketplace. I use MetroRadio Pro. I did email Pandora and let them know of my interest for an official app and they made a statement along the lines of 'we're thinking about it'.
At that point i'd say it really depends. Especially if you're looking at "a" as phone calls and "b" as texting (which are the two main uses of cell phones). I mean we're at the point where the keyboard on my phone is very comfortable and the phone calls... i got no complaints. I don't see how either one could be better. BUT if there is some revolutionary break through, such as holograms xD i wouldn't mind losing "c" for holograms!