Don’t listen to the people saying things like it’s too late to start. These are the same people who have been complaining every step of the way. Many of them now want Blizzard to rush TBC and I’m sure they will be complaining when TBC finally comes out.
Classic is a great game to start at any phase. You’ll still find people leveling…new players…alts…rerolls. I recently started an undead priest that I’m leveling now. Guilds are always recruiting and you’ll most likely find that you get geared pretty fast because most of your raid team will likely have a lot of stuff already. Compare that to phase 1 when half the raid was competing for the mageblade.