Mayor Giuliani's decision to skip a high-profile showcase for potential Republican presidential candidates this weekend is drawing quizzical reactions from some strategists and fueling debate about whether he is serious about seeking the presidency in 2008. The list of speakers for the Memphis gathering contains almost all the top prospects for the Republican nomination, including the local favorite, Majority Leader Frist, as well as Governor Romney of Massachusetts, and Senators Allen of Virginia, Brownback of Kansas, and McCain of Arizona. To stoke the presidential embers further, the conference and a leading political newsletter will conduct a straw poll at the...