Giving him more legs to 'prove' himself for a run when her term expired. It would not have served the people of Alaska for her to remain in the office (even if for only the remainder of one term) and eventually step down later for a 2012 run. If she'd been elected for a second term as Governor, the LIEberal media would still be using their poor attempt to discredit her by "abandoning her office".
Of course they will use the 'experience' angle once again since it only matters if a Republican is running. Experience certainly wasn't a factor with sHillary or DUh-bama.
The leftists (both GOP and dem plus the MSM, a branch of the DNC) will attack her now matter what she does.
If she filled the remaining 1.5 yrs of her current term, they would continue to stall Alaska governing with baseless attacks on her.
Now because of their fear of her, they call her a quitter and many (even FOX NEWS pundits, GOP and dem) declare she is off the National Stage and suggest she stay out of the limelight for now (as if she will listen to them lol)
Even if she stayed in until the end of her term and 1) ran for reelection, they would vilify her and accuse her of abandoning her responsibilities in Alaska if she also ran for president. (Unlike Obama who got paid for being a senator for 18 months and did almost NOTHING [except vote "present"] to substantiate receiving a paycheck) and 2) If she stayed in and then did NOT run for reelection for Gov, they would call her a quitter then.
LOL, the leftists certainly aren't "quitters" when it comes to lying, spinning and attacking with out actual cause.
Palin certainly didn't "abandon(ing) her office", she left in very capable hands which is better for Alaska for obvious reasons.