Ask Slashdot: Who is most likely to challenge Microsoft in the office?

Tablizer writes: Microsoft still dominates cubicle-land. Google is making a push into that domain, but it's unclear how far or how fast they can go. Most "serious" applications still run on only Windows and that doesn't seem to be changing much. What's keeping others out? Do we need new desktop-oriented cross-platform standards? It seems everyone "went web" and forgot about the desktop niche, but it's a big niche still.