But, I am also not so quick to trash focus groups, or to consider blogs an equal replacement for them. While my background means I obviously have a great affinity for observational methods of user research, I try to approach projects keeping my entire toolkit in mind: that may be ethnography, interviews, tag-alongs, and yes even focus groups and surveys.
The thing to keep in mind each that each of these tools has a use (just like I tell my husband when he uses the wrong thing in the kitchen--like the time he used the vegetable brush to scour the grease off the vent). Focus groups, while vilified by some anthropologists, can be great if the group interaction will contribute to the desired outcome. They are not, however, a cheap replacement for 10 separate interviews or observations, since the nature of the data will be different. And so, I see the benefit of blogs to get feedback on games and new technologies--knowing that these are the comments of lead users, and often trailblazers. Though perhaps the bloggers should get some compensation? At least at a focus group you get $100 and some munchies.