A WebmasterWorld thread has one person claiming he received a PageRank 7 link from the almighty Apple.com web site. After about a week, his ranking has not moved. He asked:
I'm not seeing anything measurable from Goog. How long might it take to even see a 10% boost?
The person did say he has a nice traffic boost from the link, but no ranking boost. Why not?
Could be a bunch of reasons:
(1) Google didn't pick up the link yet. (2) The link is nofollowed or blocked from passing link juice some how (3) Google manually doesn't count links from specific sections of a site (4) Just needs more time
I once saw a link on a PR 8 page by Doc Searls do absolutely nothing to rankings for the target site. It did, however, bring in a lot of direct traffic. It was experiences like this that taught me to dig a lot deeper into Google's ranking algorithm.
I don't think anyone would turn down a link from Apple, with or without it passing any link juice. So he should be happy either way.
Forum discussion at WebmasterWorld.