If you've been following the spatial forum over at MSDN, you've probably run across this thread. In short, we've ignited quite a controversy with the coordinate ordering for the well-known text and well-known binary we use for the geography type: we use latitude-longitude; many would prefer longitude-latitude.
While I don't buy into many of the arguments presented, there is one I do very much believe in: usability. As it would appear that the vast majority of data in WKT and WKB formats use longitude-latitude ordering, we probably ought align to ease the transfer of data in and out of SQL Server.
We'll be trying to make this switch in an upcoming CTP. There will be no change in the next CTP---that ship has unfortunately sailed---but we hope to make this change before we RTM. I want to be clear: this is not a done deal, and it's possible our schedule will derail us, but we'll likely make this change.
We do not intend to change our coordinate ordering anywhere else. GML, both in theory and practice, appears to use a latitude-longitude ordering, so we will continue to do so.
As always, I welcome comments either here or on the forums.