Could you elaborate why? You open the project, it is scanned and indexed. Seems logical and obvious if the IDE can sugges a relevant completion based on the whole project structure. Thanks!
While Space IS an all-in-one solution, you can still mirror a repository to it and (use it for code reviews [1]). Native integration with JetBrains IDEs should be a plus if you use them.
IntelliJ IDEA is released once a year, and smaller IDEs are about twice a year. Because of this the plugins may miss some features for some time, that's true. But now, after the release of IntelliJ IDEA they will be updated with the latest Ruby, Python, PHP, etc. functionality
You are correct, Ruby and Python plugins add most of RubyMine/PyCharm features to IntelliJ IDEA Ultimate. You may want to have separate IDEs if you need more lightweight environment. RubyMine & PyCharm are in general updated more frequently too.
Yes, you will get ALL WebStorm features in PhpStorm. They are built from the same source code. One difference: not all plugins bundled with WebStorm are by default available in PhpStorm but you can install them from the plugin repository. Such plugin is JSTestDriver, for example.
You can install Sun JDK on Ubuntu. It's not a big deal.
There are still some problems with using OpenJDK, which are being solved now. So, it will be supported someday too.
We found that screenshots on Mac _do_ look better most of the time.
And yes, you can see the trend of more and more devs using Macs. Prooflink: http://dl.dropbox.com/u/228843/RailConf_Mac_vs_PC.jpg
That was shot at RailsConf, where historically more Macs are used, but this is quite general nowadays.
