This has been asked on, among others, the Live ID blog, for several months, and no reply whatsoever. Maybe Lynn (or someone else) can answer these questions here?
1. Will we ever be able to change our sign-in email address? I know that this is possible if your sign-in address is a non-Microsoft address, but the option is unavailable if you use a hotmail, live, et cetera address. Why does Live ID provide people who use Microsoft technologies with -less- options than people who used a non-Microsoft technology to create their Live ID?
2. Account merging. IIRC, about a year ago, someone on the Live ID blog mentioned that they were aware that people were asking for this feature, and that they were looking into it. Still no word. I have two Live ID's: one I use for Messenger, and another that I use for my MCP curriculum, Channel 9, Connect, et cetera. In short, for everything except Messenger. This is a less than ideal situation: the messenger alert feature on the Microsoft forums for instance, doesn't work. You can set this up to receive an alert on messenger if someone replies to your thread. Except, I'm signed in to messenger with account A, and I'm singed in to the Connect forums with account B. You can't tell the alert to go to a different Live ID than the one you're signed into, so no Messenger alerts for me. If I get Xbox Live, I'd use Live ID B to register. However, that would make Messenger on XBox impossible for me, because you can't tell it to use the contact list from another Live ID. I have messenger contacts on account A, not account B. But B is the one registered with XBox Live. Hence: no features for me.
All this would be solved quickly if I was able to merge account A with account B (and keep the sign in credentials of account B). However, this is not possible. Why not, and when will it be possible?