As an option, you can take the SY0-101 exam if the objectives for the SY0-201 aren't familiar to you. The SY0-101 exam can still be taken until July 31, 2009. From CompTIA's perspective, once you're Secrutiy+ certified, you're Security+ certified for life.
In my experience, employers don't care which version of CompTIA certification you have. They only care if you have it.
There aren't a lot of SY0-201 study materials out there right now, but more are being added all the time.
Darril
www.syo-201.com CompTIA Security+ blog