I don't know that it's impossible, and I am all for keeping C2D for a 2011 update. I know everyone wants SB but the graphics forced with it are crap. I don't think Apple would use C2D again, as it has for four straight MBA versions and C2D is soon to be done.
Given that there have been so many C2D MBAs it seems obvious that Apple would use Sandy Bridge next rather than jumping it for Ivy Bridge. I think it is a possibility that the use of Intel's HD3000 in SB 13" MBPs could really show us all the truth about how inferior it is to even prior gen Nividia 320m and even nearly 2.5 year old 9400m.
I think there will be a lot of backlash and problems when 13" MBP buyers experience the truth of the Intel IGP. It has caused Apple problems before, and it was the root cause of the original MBA. When considering why the rev B MBA was so great it all came down to 5X graphics performance in the Nvidia 9400m.
I also think that perhaps Apple could have gotten away with SB in the MB, MBA, and Mm, but in a "Pro" Mac? It really could lead to Apple skipping SB and holding updates for the MBA until Ivy Bridge and further improved IGP.
I personally am hopeful for an AMD CPU/GPU combo or a move to an AMD discrete GPU in the MBA. ivy Bridge along with a low voltage AMD GPU could bring the MBA to legendary status.
There is hope, but it means not getting a 2011 update or a longshot separate track from MBP. MBA faithful have waited years before for updates, but the MBA is now too popular.
I don't want SB in 2011 unless it could come with an AMD discrete GPU. It appears from the 13" MBP that Apple isn't going with AMD CPU GPU combos too, but I am still hopeful the MBA takes a different track.
All I really want in 2011 is the same CPU GPU combo, backlit keyboard, Thunderbolt, IPS display, and USB 3.0. But I know this isn't happening and it's all nothing more than a dream.