Oh, I'm *all* for improved patent review at the first stage of the process. This bill doesn't have that in any serious way, though. Therefore, why not add that second layer. If you're going to do crap work in approving patents, then at least allow for a reasonable review system in situations when they're challenged.
IPBiz notes that the review mechanism is the same for the first and second window of post-grant review, so the only issue is "when" the review may occur. The "layer" at issue is one of timing, not of substance. As a distinct point, the House dropped the "second window" from its version of the bill, but the Senate did not.
There are many reasons not to have post-grant opposition at all. See Post-grant opposition: a bad idea.
In his initial statement, Mike at TechDirt had spoken of "the incredibly arcane rules that everyone is required to go through to contest a patent." In fact, re-examinations are rather easy to request. W3C even persuaded the USPTO director to do a director-ordered re-examination of the Eolas/Berkeley patent. Of course, it failed to change a single claim. Mike does not like to talk about that.
Mike's initial statement also included the urban legend: patent examiners are given incentives to approve, rather than reject. LBE (among many others) debunked that one back at the Stevenson, Washington meeting in April 2005. It's available on DVD.
As a separate matter, some people have been able to deal with "patent trolls" pretty directly. See for example an article in the IHT.
To return to the point I initially made on August 29, if bad examination of patent applications is the problem, the remedy is to fix the examination. Adding an inspection step (eg, post-grant opposition) is NOT a quality approach, as Deming would tell you if he were still alive.
As an additional point, bad patents don't just impact later "infringers." They can impact later patentees. Ask James Thomson and WARF about the enablement of certain patents cited against them as prior art.