so...what does this mean?

http://tech.msn.com/microsoft/articlepcw.aspx?cp-documentid=8354050&GT1=40000

do I HAVE to use my Vista now?  I'm afraid of changes when it comes to my computer.  I'm so familiar and comfortable with this and I'm not ready to switch over.  I guess I should but I'm just afraid that if I do something to my computer and it won't work the same.  and I do remember rkinne saying that I can install it and still be able to use xp OR vista. 

(sigh)  I don't know...