I don't think MP2's sales are a good comparison to MP3. As squirrel has noted it was released near the back of one of the biggest holiday lineups ever. It also lacked the revolutionary feel and hype of Metroid Prime while suffering from severe sequelitis. Not to mention the Gamecube was still a contender in 2002 but by 2004 all but the most ardent Nintendo fanboys were gaming elsewhere (I was moving to PC gaming at the time and generally played my Xbox if I played a console).
MP3 could be said to be in a better spot than both MP1&2. It stacks up more closely with Metroid Prime on revolutionary feel, hype, and general vitality of its console while having an install base more similar to the size of MP2 (at the end of the year at least). The only negative is it's being released in another mega holiday season but this time it's releasing first. Unlike MP2 where everyone, including me, was too busy playing Halo 2 when MP2 came out, now gamers waiting to get their Halo on will have a month they could be playing MP3 beforehand.
Anyhow, my guestimates are
1st week- 300-350k
year end- 1,000-1,200k (at least 2,500k lifetime)







