Originally posted by chromo What am I gonna do now ?
Here's another very satisfied Sigma 10-20/3.5 EX user.
It is 0.6 stops slower than the f/2.8 lens you were after, but you typically stop down a wide angle lens to f/8 or similar anyhow.
Extreme wide-angle lenses are typically not know for their beautiful bokeh and also struggle to get good corners, so stopping down is very much a standard procedure with an extreme wide-angle.
Indoors you'll probably open it up some more, but I think on the whole the situations where you really need a fast wide angle lens are rare.
When I did my research, the Sigma 10-20/3.5 was easily the better lens compared to the Pentax 12-24/4 for me.