My last car had both a Service Vehicle Soon and a Check Engine light ... so I'm assuming they aren't the same thing. My Service Vehicle Soon light came on about a week before my headlight went out, and when I replaced it it went off.
If it's your Engine light and it's doing the shaking thing, I'd definitely get it checked out. A lot of times if you go to a little oil change place they'll plug in the diagnostic thing to find out what error codes are triggering it. They don't charge a lot, if anything, to do that for you if you use all of that feminine charm.
