I'm not sure yet, Brant, but we know it needs to be done soon.

Short answer, a guess, is 2-6 weeks, if Yahoo's new "API" (the thing that BookMacster talks to at the Yahoo! server) really works.

Long answer:  This thing is a big mess.  The people at Yahoo/Delicious made this change without informing any developers.  It seems it's going to require alot of work -- how much, I don't know.  I personally worked on it for a day a couple weeks ago, trying to use a "framework" they provided which will make this much easier.  But I found a really basic bug in it, indicating that this is potentially bad stuff.  Contacted one of their developers privately.  He said they'd fix it and get back to me.  But I fear that this framework has never been tested on Mac OS X but only on the iPhone, which means there are other bugs.

Since we have plenty of other things to do with BookMacster, I set this aside, hoping that they soon will provide a tested framework that we can "drop in" and get working without too much difficulty.  At some point, I'm going to have to bite the bullet and write it myself.  The more users complain (as you just did), the sooner that day will come.  But then there's the possibility that there is something wrong on their end (in their "API") that we'll have to wait for them to fix.  I keep watching this developer forum to see if anyone has got it working yet, but so far, no:

http://developer.yahoo.net/forum/index.php?showtopic=3065&st=0&gopid=9358&#entry...

If anyone knows of any other apps that are now working with Yahoo! IDs, please reply and indicate it.  At least then we'd have confirmation that it can be done and that efforts will not be wasted.