Conventional wisdom on the forums seems to think that outbound links bleed off PR. I've heard a few say that outbound links to high PR site actually help. Does anyone have an authoritative answer?
I don't think anyone can say for sure but that is the general consensus. In my opinion the best of both worlds is to go ahead and use outbound links but make sure you add the "no follow" tag to them. This prevents your PR bleeding to other sites. Conversely make sure that links back to your homepage from other pages on your site DO NOT have the no folllow tag.
Logic: Why every site doesn't link to high PR site, like Google? Because there is no use of that. Many outbound links can be considered as spamming, links selling (especially if you link to not related sites).
I think the best answer is: Stop worrying about it. If your content calls for a link (or a bunch of them), go ahead and link out. Just do whatever is natural. And IMHO, nofollow was made to represent an "untrusted" link - a link you can not vouch for. It's improper to use it for _all_ your outbound links. If everyone did that, there wouldn't be any link juice passed to your site either.