Should I upgrade to SBS 2011 or Essential 2012?

Hi,

I have SBS 2008. Everything works fine now. My questions are:

1. Should I upgrade SBS server?
2. If I should upgrade, should I go SBS 2011 or Essential 2012?
3. I know Essential 2012 doesn't include Exchange, so what to do with Exchange after upgrade to 2012?

Thanks in advance!

Grace