This is another announcement I wouldn't have guessed would happen. This is pretty awesome. You can get both Metroid Prime games for cheaper than they would be as NPC games, plus you get the third game. It's great for people who haven't gotten the third game yet, great for people who missed the first two, and even great for those who are itching to replay the first two games with Wii controls. It's win-win for a lot of people really.
I'm kind of curious as to why they didn't wait to announce this until E3. It really makes me wonder if they are going to have any game announcements or just showcase Wii Motion +.