Just as a marker to see your point of view, who would you view as a conservative? And why?
Let me answer your question another way. Break it up into categories:
Foreign policy. Even though defending America is, regrettably, only advocated by conservatives today, it is not, traditionally a liberal/conservative divide. JFK, Truman, FDR, HHH, and Scoop Jackson come to mind. So by the standards of the last 30 years, W scores as conservative and a top notch president in foreign policy. In the longer term, the new lefters will die and defending America will become, again, a relatively non-partisan issue. So I'm not sure how this factor cuts in my analysis.
Spending and the Power of the Federal Government. Conservatives do not support programs like the prescription drug program or the NCLB act. Nor do they support the drunken spending spree our government has conducted the past four years.
Liberties. Conservatives do not support silencing political dissent in the 60 days before an election.
Social Issues. The true test on this will be who W nominates for the supreme court and how hard he fights for them and for the nukular option. The jury is still out on this one. Some of his acts are consistent with social conservatism (exec order prohibiting funding abortion mills at the UN) and some are not (supporting affirmative action). To date, modestly conservative but he could score big with his supreme court nominees.
So he comes down across the board. Looked at from a traditional small government conservative viewpoint (which is mine), he is moderately left. I think those who consider W a conservative just show how desperate conservatives are for any slice of the political pie. Don't get me wrong, he's WAY better than the rats. But we are so far from the land of conservative governance that you cannot find a map to get there from, even a Republican dominated, Washington DC.