The biggest problem is that Apple is probably the closest internet-based distribution system to the record labels of old. Perhaps this is an "appeal to the masses" approach or to get onside with the labels.
The downside of this is that a collaborative filter based on genre and sales will never go deep. I doubt they'd ever use pearson's correlation coefficient seriously enough to offset the "this is the new hit everyone listens to so you should too".
I guess it comes down to musical integrity to the extent of ignoring trends to deliver truly accurate results... or hit 90% of the market with a simple solution that probably makes them more money and makes the record labels easier to deal with.
Glad to see they're thinking different and aren't just playing to the status quo.