Our favorite analyst encounter is when you get close enough to something important that the vendor feels a need to correct the details. I had a chance to do that with Microsoft to get some of the specifics of the Windows communications improvements. We're going to do a report for clients on the topic (it's important enough) but here's the gist. We had called the new TCP/IP stack "Chimney" (to be fair various Microsoft people did too in early discussions). In fact the new stack doesn't have a catchy name whereas Chimney is really an orthogonal architecture that deals with the transparent insertion of hardware assist capabilities for which TCP/IP acceleration (via Intel I/OAT or full offload) is the first big example. Aside from the terms (which, all kidding aside, it's important to get right) what's hard to really understand is that the communications improvements that Microsoft is putting in Windows: (1) is free (just shows up with some new system or O/S upgrade); and (2) in fact ubiquitous given the dominance of Windows as a desktop platform. This is very different from what other vendors sells which is for purchase acceleration of specific links. Understanding the impact of these improvements overtime is complicated by the facts that you have to make guesses on the spread of Vista and Longhorn server, and some benefit is achieved even if only one end-point is improved (e.g. Vista to WS 2003 rather than Vista to Longhorn). In our client report we're going to try and deconstruct it so the high order bits are easy to understand. Finally, in our recent report on Cisco WAAS we said that MS used "non-standard" elements of TCP/IP which in a precise sense is also wrong. The WAN improvements in the new (unnamed) stack are all in accordance with some IETF RFC -- they aren't non-standard, they just aren't what everyone else is using. As they used to say about the ISO Standards, all the incompatible versions were standard implementations. In this case, things aren't nearly as bad because the new TCP/IP stack will work with everything else, it's just the benefits won't accrue unless the other system has the same standard but not conventional features implemented. In practice this means another MS system, but that's not to say it's a proprietary feature, if you follow that (in my next life I think I'll work in the Vatican clarifying Catholic doctrine minutia).
