Resolution bumps are a mixed blessing. Text can be very hard to read at high resolutions.
I think higher resolutions are more likely on MBPs released with and after 10.7 because it would require bigger menus and chromes.
The 27" iMac and the 17" MBP screen resolutions stretch the ability to read text on many web sites.
Wait why would text have to get smaller at higher resolution? Can't you just bump up the text size to compensate?