Avantgo hasn't been working right for a long time anyway. I used to have it on my original Palm Pro and on every Palm device since then. It was great because it would give me content to read on the plane that didn't require wireless. But it was always quirky on the Treo and even more so on the Blackberry. When free content like Heavens Above disappeared, and sync problems increased, I finally lost interest. I had a good experience with Avantgo in the old days, but I guess their time has passed.
But, an SMS service? Sounds like another number I have to lock out of the family phones. $100 in charges to kgbkgb in one bill (kids!) has absolutely killed any interest I might have had in SMS services. They're for suckers. They're this century's AOL -- offering for a fee what anyone with an ounce of sense could get for free on the internet.
I think there is a use for fast, simple, text-only information services, but I don't think sms is the proper mechanism. If web designers would stop trying to make wap pages "a rich experience" and just provide the damned information in a simple and fast-loading manner, mobile web services would be a heck of a lot more practical.