Update on the Specter legislation: Yesterday, Sen. Specter (R-PA) spoke on the Senate floor and submitted into the Congressional Record (starting with page S10230) the text of his proposed immigration "study bill" and the letter he sent to his fellow senators. The text of this bill is pretty long (it goes from S10231-S10300). You can find a full text of his remarks and the bill here.
A lot of Specter's draft seems to mirror the language of earlier proposals--except it does not include a direct "path to citizenship" for the legalized and does not necessarily shift the (extended) family-based emphasis of the current legal immigration system. But there are a lot of details, so there may be other differences. It also has a "guest worker" provision. I don't know how much support for this measure there is in the Senate, but Specter says that some responses to this proposal are "enthusiastic." CQ says that Kyl is doubtful that the Senate is that interested in reviving this type of immigration "reform," but Specter thinks there's some "momentum" for his proposals. Time may tell how much momentum there is...