Ok, Matt Cutts gave a talk at
[Only Registered users can see links . Click Here To Register...], where he leaked out, that page rank at least affects crawl rate.
If anybody is interested, I did a little analysis of the crawl rate depending on PR, by comparing a PR5 with a PR3 website. There were quite a number of things to consider for doing this, so I'll have to refer to my blog for the results, instructions and tools used.
For those wanting the ultra short and totally inaccurate summary: Going from PR3 to PR5 increases crawl rate by about factor three (don't quote me on that, though)