[jussij]

Here's my 20+ years of experience working as a contract in Australia.

In all that time I've only ever worked with proprietary tools and have never had trouble getting high paying contract work.

I would say I've done very well betting on something proprietary.

[hkarthik]

Parent comment had to be qualified a bit: Never bet on anything proprietary which doesn't offer significant advantages over non-proprietary competitors.

[nextw33k]

Sliverlight would be a great example of that.