.NET Reflector started out as a free utility written by programmer Lutz Roeder and quickly became fairly indispensable to a lot of programmers. After about four years he sold it to RedGate software, who has maintained a free version ever since, as well as a "Pro" version about a year ago which adds capabilities and starts at $99/seat.
The new version will no longer have a free version, will be $35 for the non-Pro versions, and the existing free versions will still work until the end of May.
On the one hand it's annoying that the existing free versions will die and obviously I'd prefer there be a free version going forward. On the other hand I respect where RedGate is coming from and the cost for a license isn't prohibitively expensive. Plus it may encourage more frequent updates.
EDIT: I originally said it was $35 for everyone but according to this FAQ there's still going to be a Pro version.