Like I said, I basically use my MSN account, but several months ago when there was a hack available to get a live.com address I registered firstname.lastname@example.org. I have linked it to my MSN account but in general I use my MSN account unless signing up for a service where SPAM can be the consequence.
I was never a fan of hotmail, just the name scares people or seems like some dating or junk mail service. I tried it way back when, before Microsoft bought them. Sure you can keep your hotmail address, personal choice, convenience, whatever. I think anyone considering getting a new live.com address needs to understand a few things. Much like a hotmail account it is free, although you get some great benefits in terms of allotted storage and services, a live.com address still includes advertisement banners and the things you see with hotmail, that I don’t get with my MSN account. The new Live Mail service provides a nice tool for switching over (also includes migrating from gmail and a few others). However if you started using Live Spaces, there is no easy way to migrate that. Things like Messenger are basically handled with the e-mail switch over utility there just is no rename my existing account functionality. The switch over tool is pretty cool https://secure5.trueswitch.com/winlive/ .
I am not advertising MSN at all, actually I think Microsoft is really leaving the paid MSN subscribers out in the cold.