Would rather just wait for Ivy Bridge to be honest.
Ivy bridge won't be hexcore, for the things you'd actually buy SB-E for Ivybridge will suck in, as in, having 6 cores, needing more memory slots, needing more bandwidth.
SB-E though for 99.9% of people is entirely worthless, gaming it won't offer anything except higher power usage and the same performance. Encoding/rendering it will all be faster in but for "normal" people you've got to ask yourself if you need to spend £400 more on a hexcore than a quad core normal Sandybridge, for the two encodes you do a month, to save 2 minutes off each one, the answer is now.
As always, if you make money based off the work you do and its cpu limited so a better CPU will help you finish work faster, do more work, and get paid more, then its great, if not, worthless.
I really don't know why you'd go for a Sandybridge-e if you're moving just for the memory, you could have had a £200 i7 1366 years ago with 24gb memory very easily if you're memory limited.
To be honest, I'm sure you could EASILY put together two normal 2500/2600k systems for less than the price of one top end SB-E system aswell, all for studying for certification and not even for work, screams of massive massive overkill.
Not much point in waiting for Ivybridge either though, a little lower power usage, meh, no noticeable performance boost except for people who use the IGP a lot. Sandybridge now rather than wait is the pretty easy choice to make.