Time's running out for the upgrade deal and I haven't even looked at Melodyne yet. I don't bother with pitch correction, but I would buy it if it could help me pull timing info. I have real trouble with setting a metronome.

Yes, it can. I am not sure how wide its analysis window is though, as it does shift while playing a track.
 
I just realized I misread your title... the bpm it will calculate automatically, but I "think" the time sig defaults to 4/4 regardless (but not sure on this one).

According to the manual it can but I have not tested it:
 
"The time grid must correspond to the musical content before any sensible editing of the audio material is possible. Whilst Melodyne Plugin assumes that a transfer matches the tempo of the DAW as indicated by its metronome click, Melodyne Stand-Alone analyzes the audio file loaded and deduces from the material itself the intended tempo and time signature. Since, however, this is, at the end of the day, a matter of interpretation, you do need on occasion to adjust the grid manually after the detection. In this tour, you will find out how this is done.
 
Within Sonar (or any DAW) it adapts to whatever time signature change the user makes.
 

I tried to see if there was a way to do it within Sonar but gave up.  I would guess you would have to bypass the ARA integration and use melodyne in fx bin instead of as region fx.  It worked just fine in standalone although a couple of 6/8 files came up as 3/8

Thanks for that. I couldn't get it to do anything so I'm assuming I lack the basic brain power. At least I'm smart enough to know when I'm too stupid for something.

Lol.  have you tried in standalone mode?

Dub has a good point which I neglected... when running in ARA mode Melodyne initially locks onto the X3 time signature. It will only calculate things on its own in stand-alone mode.