That's basically my point, said well and much more succinctly than I'm ever able.
Almost every feature Apple touted when introducing MobileMe I kept thinking, "Wow, ______ already does that for free." "Ummm... _____ has been doing that for years." They talk it up, put a pretty bow on it, and charge you. Basically the answer is, if the @me.com email address + having those features set up by putting your password once in System Preferences vs. having a few webpages bookmarked, go for it. But I'd spend the time left on your trial account figuring what about MobileMe attracts you most and compare those features to other options for using them.
MobileMe is to calendars, contacts and email as AOL is to ISPs. It's sub-par features and service delivered prettier (for us aesthetic folks) and easier (for those who wouldn't use those services otherwise) at a significantly higher price.