Inkscape 0.49 will now be Inkscape 0.91
The topic of version numbering has been discussed many times over the years. The original version numbering scheme was tied to our goal of having full support for the SVG 1.0 standard. We've decided that it was time to change it to better reflect it's maturity as a vector graphics editor instead.
We still have other objectives that we would like to complete prior to releasing 1.0, but this was a way for us to get moving forward on that path.