Just this past week, I've started on Blender. I've been following it loosely since the late 90s, but this was my first real go at becoming proficient. I first tried 2.49, but found it extremely aggravating. Moving to 2.5 was a tremendous improvement, making Blender's unusual workflow slightly more obvious, but there's the rub.
Blender, in its origins, was designed with a very different set of basic interactions than the leading 3d animation packages. In time, as they've added more features, they've slowly moved the experience to be more in-line with Max and Maya, but these alignments apply pretty much exclusively to the newer, high-level features. The core interactions for moving/rotating/scaling, viewport movement, selection, and other "basics" are completely different.
If anyone else is just picking up the program, I'd encourage you to share any good resources or tips you've found for overcoming the initial grind. Here's what has helped me most:
Take notes of all the keyboard shortcuts you encounter. Sure, there are existing lists and cheat-sheets, but writing them out has really helped me memorize them. As I'm following the BlenderCookie videos, I watch for the interactions I don't yet know and immediately jot down the details. Don't forget, many of the commands are highly context-sensitive.
I use it for everything: App Icons, textures, explanatory animations, diagrams, and of course 3D. Try it, it's incredible (though the documentation needs some love)
Working with blender is fundamentally different at the most base, intuition-sensitive level. Not better or worse, but different.
It will be worse if you're coming to it already familiar with Max and Maya. You'll rub against the grain of the program. Of course, the same is true of moving between any programs that are cosmetically similar but based on different interaction models.
I found MAX very easy to use. Maya was harder, and Blender (before 2.5) was extremely difficult to learn. With the 2.5 release, though, they really improved usability of their program. I'm really surprised, and am now trying to use Blender for everything as I enjoy it most.
http://en.wikipedia.org/wiki/Blender_(software)#Use_in_the_m...
Studios usually don't advertise the tool used in a production to the general public. The trend is shifting in favour of tools like blender though. Blender is also doing a lot of heavy marketing to those segments through their open movie and game projects. I can see a day in the future where studios contribute significant developer time to a project like blender in lieu of expensive licenses for something like Maya or 3DS.