Only thing that keeps me from switching is the fragmentation and the speed of updates.
I understand they are going to slow down the speed of update revisions when they release Gingerbread, so hopefully by this time next year the Android Eco system will be alot more stable.
Alternatively they should bring out raw Android devices without Sense/motoblur/samsung crap on top.
They did, it's the Nexus One, but because of Google's strange decision to sell it direct and only through their webshop theres only about 250,000 of them in the wild. Everyone else seems to have gone for the Desire or the Galaxy.
While the 2.1 v vanilla UI of Android left a little to be desired, 2.2 vanilla is as good as Sense on the other HTC phones. In fact the only things I actually miss from Sense are some of the widgets, and that's only really a cosmetic thing, as there are other widgets that do the exact same job, but just aren't as shiny.
I think though, that most devices with custom UI allow you to disable it (i know the Desire does) and use the vanilla launcher, but the issue from this article is less the customisations done by the phone manufacturer, and more the random bloatware s**te that every carrier loads, or features that they remove (i.e. Tethering). Unfortunatly this is the problem with virtually all carriers and all phones (just look at the iPhone in the US, even though it's capable of tethering, it's disabled unless you pay something like $25 for the priveledge).
Vodaphone recently pissed off a bunch of their Desire userbase with something like this. Theey pushed out an OTA update that everyone thought was the Froyo 2.2 update, except it was just a whole shed load of vodaphone bloatware, which you couldn't then un-install (well, you could, but it involved rooting your phone iirc)
TL;DR Mobile phone carriers will always try this s**t. An open OS makes it easier.