tedster - 10:02 pm on Jun 9, 2010 (gmt 0)
Just so I'm clear, are you talking about a possibility of 16! (factorial) possible pages - like 2 followed by 13 zeros? Or is there a likely limit to the number of option combinations selected at one time?
That kind of dynamic tag creation can be a nightmare. If you make the pages technically crawlable, then some of them may be crawled - but only crawled, indexed and ranked because of other factors, inlcuding backlinks. Just being a form selection probably wont do it.
As far as the title element, we can see that Google truncates the display around 70 characters or so, but they do seem to index slightly longer tags - how much longer is an open question.
The meta description is not a ranking factor. Rather than create duplicates (and doing it dynamically sounds like that would be inevitable) I'd probably let Google build their own snippet in cases where the page actually ranked.
I'd also be concerned with generating the url for that kind of page. Bottom line, it doesn't sound like the kind of content that Google wants to index - but I say that without knowing critical details, of course.