The surplus is the result of an improving housing market and economy in general as well as the tax passed last year. Brown has also done a good job trimming the budget the last couple years. He has pissed off some of his own constituency but he has been a solid fiscal steward.
A decent chunk of the money for the tax increase went into education already, so I would rather just use the surplus entirely for the rainy day fund, as we still have significant fiscal issues long term. Don't piss it away on spending, just lock it away.