The New Peer Review: Trial by Twitter

An important distinction is peer vs. critic. In many cases, the uproar in popular media is created by uninformed sensationalism. Journalists with deadlines and without backgrounds in niche fields just can't formulate meaningful criticism. Peers, on the other hand, provide reviews in a slower and more private manner, but it's responsible.

If it were faster and less private, but still constrained to peers, then by all means: this would be great. The concern is signal to noise ratio, with a furor of uninformed voices drowning out the meaningful discussion among peers.