For a while Plaxo was having issues syncing with Yahoo! so they removed it from the list.  As of this weekend it looks like the Yahoo sync is back in business.  Which is good because I was actually starting to look in other directions for calendar and contact management since Yahoo! is where I do all my emailing from.  Also looks like they did some UI updates and now I have a pulse icon on the toolbar, don’t know what I think about that yet I will have to let you know after a few days.