I'll be the contrarian here and state the belief that this ruling isn't so good.
The major issue, of course, is that there is massive abuse to the system, but if you look at what the system is supposed to do I think this ruling turns things more decidedly in the favor of large companies.
The idea of the patent system was that anyone could patent their grand idea and then have legal backing to protect it in court from someone that uses the idea without consent. The filing fees were also designed to be low to keep the barrier of entry low enough that "the little guy" could get the same protection as the big corporations.
Prior to this ruling (ignoring the shake downs by trolls) an individual or small company had a chance of winning a patent case against much larger entities (motions and legal wrangling aside) as the process of discovery forces the defendant to show their cards and prove they aren't infringing with no upfront cost to the plaintiff.
With this ruling, if you come up with the next great search algorithm (software patent absurdity aside) and Bing/Google/Yahoo steals it you now have to foot the bill for the discovery. Without the court order you also aren't going to get very far in that process as they aren't exactly going to welcome you into their office, sit you down at a console, and give you access to their code.
So what this ruling does, in my opinion, is give the larger companies the right to violate patents from smaller entities with near impunity. It also (as someone suggested further down regarding OSS projects) gives rise to a whole new possible "reverse-patent" trolling business scheme.
Basically this ruling, I think, has made things worse.