I want to play this game, but the only places I can buy it is to get a physical copy. Not even steam, or their website have it. Plus the sequel is coming out, and you'd think that the developers would want people to play the first.

It isn't likely it'll be released as digital anytime soon, considering EA hasn't released any games prior to 2006 or so as digital anywhere, not even best sellers like The Sims or Black and White, although SimCity 4 DID get a release. It is, however, sort of likely it'll get a digital release once Madness Return looms closer, or even when it releases, but even then, the chance of it being in GoG is quite small, since EA and GoG haven't signed a deal for any games yet.