First, while Blue Coat grew up in Web caching, Packeteer's strength has always been deep packet and protocol expertise. The two technologies complement each other quite well, covering the gamut from application to file access acceleration.
The other thing Blue Coat gets is scale; competing with Riverbed and Cisco Systems demands deep pockets and feet on the street. Blue Coat gets bigger instantly. All in all, it's good for Blue Coat, bad for second-tier WAN optimization folks.
On another note, I want to issue a mea culpa to the folks who run the RSA Security Conference. In a blog last week, I relayed the multitude of complaints I heard from exhibitors about the prices they had to pay for things like cases of water, chairs, and tables. My blog may have inferred that the RSA Conference organizers were responsible for this highway robbery, but that is not the case. Actually, RSA only passes on the costs demanded by the Moscone Center, so the extortion lies with the venue and not the show itself. I apologize to the RSA Conference management team for the confusion.