Can I use the WeDo USB hub with normal Linux distributions?
Lego's education catalog implies that the WeDo software is required for the hub to work. It states:


  The two-port hub controls motors and sensors, transmits power and data
  to and from the computer, and is automatically detected by the WeDo™
  Software when connected to the computer.


I found some info regarding WeDo software, the manual has this to say:


  Q: What is the full detailed information on the compatibility with different platforms?
  
  A: The WeDo™ software 1.1 is supported on Windows XP and Vista operating systems with the latest service packs. It is also supported
  on the Mac 10.5.xx operating system with Mac Intel processors. A
  minimum of 512 MB Ram is required and 300 MB of hard disc space. The
  WeDo software 1.2 is supported on Windows XP, Vista and Windows 7
  operating systems with the latest service packs, as well as the Mac
  10.5.xx and Mac 10.6.xx operating systems with Mac Intel processors.


In general, Lego software seems to be supported only on OS X and Windows XP, Vista, and 7. All of the software mentioned in the Lego catalog (Lego Mindstorm Education NXT Software) indicated support for OS X 10.4 or later, and Windows XP, Vista, and 7. Linux support was not mentioned.