Jantje.
I don't think people understand the amount of work that it takes to build and support a serious library or a development environment. If they did they would not expect it for free.
For instance, how many hours have you spent on your Eclipse plug-in for Arduino. I would guess in the range of hundreds. That is not something you put together over a weekend. Great job BW!!!
Here are some numbers that might be of interest. Developing software within a 10.000+ organization/company takes on average 1 hour per line (approx. 10 lines per developer per day). That is total cost, testing, documentation, project management, etc. There is tons of statistics that points to this. Actually the number drops for embedded and time critical software (See COCOMO - Wikipedia, more links below).
This implies that 1000 lines of software costs in the range of 100.000 dollars/euro to develop and maintain. Making a copy/downloading costs more or less zero 
Now a small startup software company (<10 designers) can produce as much as X10 per hour. But after a few years/projects when they have to maintain legacy, have to hire, etc, productivity drops. The numbers are more or less constant for different programming languages, though components and abstraction helps get the most out of the 10 lines per day per designer.
Please note that device driver and real-time software are the most expensive to develop.
My guess is that there are many companies (and people) out there that would be willing to sponsor specific projects. The problem is handling the "projects" and knowing that what they are sponsoring. Kickstarter is great but it is difficult to apply to software projects as it is difficult to display the intended "product". Hardware is so much easier. One way forward might be to make at least some library maintenance sponsored through for instance licensing of the Arduino software, e.g., "a dollar" per board could be put on software development.
Cheers!
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