That's weird. When you used to have the option to play WMV or RMV, did it appear in the same video player, or did a new window open? How did you know you were watching WMV or RMV?
Most, if not all of the interface is made from Flash, which would explain the Flash Video option always being available. It is possible that they got rid of the other options in favor of one option. This would make the most sense, as Flash is not browser or OS dependent. I've made a few websites in the past, and the biggest streaming media problem as finding a solution that was not ridiculously complex, but would work across all platforms. For instance, windows media video would be the most viable option, as the majority of people out there are using PC's. However, using WMV and WMP browser plugins meant that there were many MAC people out there who would be alienated due to missing codecs or flat out refusal to use anything windows (rich boy snobs). The opposite was true for Quicktime. These days, codecs and plugins are a little more user-friendly across platforms (hell, we even have windows on macs), but Flash is something that is on every computer and is alto easier to work with than any other type of media file.