Flurry of interest in LG post?

Not long after the news that a Pittsburgh councilwoman was considering a primary challenge to Lieutanant Governor Knoll (see here), rumor now has it that other state heavyweights are considering the post, including onetime Senate hopefuls Barbara Hafer and Joe Hoeffel. Is all this interest a symptom of Knoll's perceived weakness, or of a new view of the LG post as a possible stepping stone to the Governor's spot? Maybe any excuse to keep one's name in the news...