Alaska would still suffer a large number of lawsuits by Democrats mostly from the lower 48. This would just be used to reinforce the belief that the lower 48 are out to get Alaska. States like Alaska tend to view outsiders who come in and tell them what to do badly. When I lived in Nebraska it was very similar.
She would have easily won re-election, and to be honest I doubt it would in anyway dampened any of her assistance to others in the 2010 elections. If she were still Governor she would of probably have an even larger profile thanks to the continued lawsuits mentioned above and the fact everyone would assume she was just waiting to run for President. So, her every move would be tracked even more closely by the media (if that is even possible). However, if say a lot of big liberal donors thought they could get revenge on Sarah by supporting the Democrat (Berkowitz, OTL), then all the money they would waist in Alaska is money that could not be used in other elections. That may have made the difference in a few close democratic wins OTL, which would now be losses.
I doubt it really matters, in regards to election prospects for President. Our current president had no executive experience, so that is hardly a disqualification anymore. Also, to any potential supporters she would have in 2012 would be there whether she stayed Governor or not. To be honest I seriously doubt she is going to run, and I am someone who would gladly vote for her over the current President. In the end I really do not see where she benefits, being President really is not as great as it objectively may sound. Lastly, I do find the media and liberal obsession with her amazing to down right scary. My liberal Massachusett Democrat parents practically track her every move, where I could care less where she lives, visits, etc...