[W]hy have Universal decided to apply pressure at this point? Are they thinking like Grooveshark suspect, that they can bully their way into a deal with the streaming service without having to give away a rock bottom streaming royalty rate?
Unfounded speculation: maybe they've somehow found out that Grooveshark is finally making some decent money?
Or they have a lot of seed capital, and universal thinks why not take their money. My guess is that they haven't found a way to make much money from this arrangement. The bandwidth and storage costs alone can't be offset by advertising alone. VIP and pay for services are required. Now paying royalties for per play music makes this whole model very unworkable. The royalties imposed by the big 4 are a much more efficient way of preventing such models from taking shape than legal threats. So, legal threat -> resource starvation and legal thread -> royalty deal -> resource starvation. Same outcome, but the big 4 have more money now than doing just the legal route.
Unfounded speculation: maybe they've somehow found out that Grooveshark is finally making some decent money?