Well it was similar to the MS conference in that it had no major announcements. However, it did have a lot of interesting smaller announcements.
We got dates for Mario Galaxy and Smash, Metroid Prime 3 and Zelda DS gameplay footage (the wait just got harder), Mario was shown flying around in an awesome little bumble bee suit, Mario Kart and Wii Fit were announced (not entirely unexpected), a couple neat peripherals were revealed, and Reggie declared a crusade to make the world safe for Nintendo. In addition, we got the vintage Nintendo old secret answer, new secret planted (such as Duck Hunt with the Zapper? Who exactly is new to Mario Kart, Sonic? When is Wii Fit going to begin dominating the country?).
I think any hard core gamers who think Wii Fit is a joke are going to be in for a sad wake up call when it owns Halo 3, Killzone 2, GTA 4, and whatever other mega hard core game is out there. I wouldn't be surprised if it turns into the console version of Nintendogs, it'll probably be in the top 20 3 years from now.
Anyhow, it did lack any really mega announcements but it was well produced and did what press conferences are supposed to so I'd give it a B, maybe B+ (although the 12 year old Nintendo fanboy reawakened by Reggies call to arms demands an A+++).