I just read a post on Steve Kaufmann's blog about language learning and Web 2.0, which included a link to this YouTube video he made on the same topic. As a guy experimenting with creating Web 2.0 language learning applications, I feel like this message is aimed directly at people like myself.
I completely agree with the general message of the video: Focusing on grammar in language learning is detrimental and yields very little in the way of actual proficiency in using the language. But its the specifics I keep getting hung up on.