While I don't know TBH they sort of just started 65 nm process so I wouldn't expect to see 45nm released any time soon.
I'd say if there was to be one in 2007 it would be more Q3 or Q4 but I've heard nothing on it and don't anticipate a 45nm release.
Intel's 45nm is supposed to go online next year. The first 45nm chip is Penryn, a mobile CPU and successor to Merom. Penryn will spawn two desktop cores, Wolfdale and Rigefield. The only difference I know between those two cores is that Wolfdale has a 3MB L2 cache, wheras Ridgefield uses a 6MB L2 cache. These are set to be released in early 2008, which means that they may not have a long shelf life if Intel sticks to their aggresive roadmap and releases their next-generation Core processor, Nehalem the same year. Other chips include Yorkfield (8 Cores), Bloomfield (Native Quad-core), and Perryville (2MB L2 Single Core).
Cores have been know to mysteriously disappear from development, so don't neccesarily expect all of these to show up if Intel has problems.
To answer your other question: I think it's too early to tell whether any current chipsets will be compatible with 45nm processors. Given Intel's track record, I'm inclined to say no. I would assume that the Bearlake series of chipsets being released next year will be.