For those of you that may be after developing Microsoft C# and other .NET languages on Linux through the power of Novell's Mono, the first beta release of MonoDevelop 1.0 is now available for download. MonoDevelop is a GNOME IDE for these Redmond languages as well as C/C++ development support through g++ or GCC.
The mono patent situation really scares me, I just don't trust Novell and all their deals with Microsoft.
I'm gonna stick with Java for my development now that it's GPL. It's not perfect by any means, but it's a solid language (OOP, Unicode, Threading, etc). I find the latest Eclipse release really great once you get over the initial hump of learning how it works. The new Java-Gnome bindings also seem to be progressing well, and combined with Java shipping out-of-the-box with upcoming distros should make for a powerful Linux development platform: http://java-gnome.sourceforge.net/4.0/NEWS.html