Keyless entry systems worry me. They are like garage door openers, a huge security risk. I'm not sure how secure they are currently, but if they are regular RFID, I would rather not have it. At this time, I won't get an RFID enabled CC because they are just too easy to hack:
http://www.mobilemag.com/content/100/102/C14871/
I would just rather have a key and alarm system at this time. Fool proof, not in the least. However, I believe RFID would make it much easier to steal my car than good old fashioned key and alarm system.
On the other hand, if they do something along the lines of finger print scanner, that might be better depending on how it is implemented.
Anything can be bypassed though, my only concern is making it too easy for the thieves.