Neat-o - I love travel (and I am a little obsessive about it) and I love games, of course, so this is a cool idea - a list of top gaming destinations. Of course, as the article mentions, you aren't guaranteed to get in to something like E3...
I'd personally make some edits. First, I'd move PAX waaaaaay up near the top. If you're a gaming enthusiast, I'd say it's WAY more fun than E3. And E4All? Hm, I didn't go so I can't say, but it does seem a bit early to put it in the top ten. I would drop it from the list until it had a chance to prove itself.
And I'd add the GDC to the list. GDC is expensive, sure, but if you can swing a student pass, submit a talk, or get in as press, you're guaranteed to encounter talks that make you think, game developers who are exploring exciting new things, and some important reveals, too.
It's not electronic-gaming focused, but GenCon definitely needs to be on there, too. GenCon is giant, a true geek gamer's paradise, and increasingly, boasts some interesting electronic gaming content.
And while yes, Mountain View *is* home to a lot of high tech companies, it's very office-parky and not that much fun to tour. They'll probably throw you off the Googleplex anyway. It's probably a better idea to come to San Francisco around GDC time to partake of all the parties and all the open houses hosted by local game studios.
And finally, I should point out that any vacation can be a terrific gamer vacation if you take your DS along!