Just heard on Air America (paraphrased): "how dare Kerry try to suppress allegations against him by suing the SBVT group over their ads, blah blah blah, if Bush had tried to do the same thing he would have been excoriated in the press."
Media Matters is all over this: Bush did indeed threaten to sue to suppress an unflattering biography that came out in 1999 (over a year before the election). This bio got almost no media coverage, in contrast to the swiftees--but the swiftee ubiquitousness is partly a result of their massive publicity campaign (buoyed by some serious donations). As with the swiftees, the purveyor of the questionable allegations had a pretty questionable background of his own. After Bush's threats, and after negative information about the author surfaced, the publisher pulled the book.
But the two cases are not comparable. Bush threatened to sue to prevent the book from being distributed, aiming to suppress the contents as much as possible. In contrast, no one could honestly claim Kerry is suppressing the swiftee's story, which has dominated the news for nearly two weeks.
Instead, Kerry has filed an FEC complaint, not only accusing the swiftee ads as "inaccurate", but also claiming that the organization has "illegally coordinated with the Bush-Cheney presidential campaign and Republican National Committee".