Yahoo! Maps is here
And it's not bad at all! The use of flash instead of AJAX is an interesting differentiator from Google maps. But they also have the AJAX version available as part of their APIs, along with a simple and flash version. They seem to have done their homework, their beta version being much more advanced than Google's at launch.
As always, TechCrunch has an indepth review, as does Y! Search.
I'm loving this. More later ...