270 vs 620?

I'm planning a certification path for myself and I'm trying to decide between 270 and 620.
While I'm very familiar with XP, I think it might behoove me to study for the 620 and become more diverse in my OS knowledge. Another thing I'm considering is the move to Windows 7. From my experience, 7 feels a lot like Vista, so I think I may kill two birds with one stone by taking the 620 since it will also familiarize me(somewhat) with 7.
Thoughts?
While I'm very familiar with XP, I think it might behoove me to study for the 620 and become more diverse in my OS knowledge. Another thing I'm considering is the move to Windows 7. From my experience, 7 feels a lot like Vista, so I think I may kill two birds with one stone by taking the 620 since it will also familiarize me(somewhat) with 7.
Thoughts?
Comments
Most everything youd learn for Vista will be good knowledge for Vista, but newer and most desired by companies. The 7 test is also a lot more geared towards enterprise and not just "basic" knowledge.
However, I don't see the 680 listed as an option for the MCSA/E on Microsoft's site. Is it safe to assume they simply haven't added it yet and it will be included as an option for the requirements?
On one hand, I'd like to stay ahead of the curve. On the other hand, I don't want to be so far ahead of the curve that I'm certified on things that a potential employer isn't planning on upgrading to any time in the near future.
peace
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