I'm pretty sure Kalcor said he disliked the idea of an "automatic" updater awhile back, but it could be feasible if tweaked e.g. a pop-up message on the side of the client that informs of news/updates, etc.
I think it would be a way to keep the updates faster and not forcing the player to come to the forum/site to download the new version. After then I present a design idea sketch for a modern SA-MP launcher.