Sony should offer a free premium avatar to cover the grey box if this turns out to be what they are doing. Its a great marketing technique "if you dont like the grey boxes get out your credit card and pay for a sleek design".
If they integrated top game packs - where you got a dynamic theme and premium avatars (more than 1 otherwise it would be a rip off) for a set price, then I'm game.
Anyone imagine snake around their XMB profile (with possible trophy stats) - it would look great!
Still its speculation and they might just give us more coloured poo to replace the grey boxes