1. list tests with quick filter (preview test selection)

To list the collected/matching tests, just add the '--collect-only' option.

 not opposed to this, but I'm not sure if it is really worth the effort to maintain something that just obscures the options. Most "users" will probably just run the test script without any options to see if all the tests pass. The "developers" are the ones most likely to be playing around with options, in which case we just document the few options I've mentioned above that covers 90% of the use-cases. It is then up to the developers if they want to dig into the options further by using the '-h' option.

From python2.7 the unittest module has decorators for skipping test[1], but for the foreseeable future Roundup also supports python2.6. The pytest has its own test skipping decorators[2] which has support for python2.6, so if we were to take advantage of that we would be tied to using pytest. If we drop support for python2.6 then we could use the unittest skip decorators instead of the pytest ones.

I don't have a preference, but it would be nice to keep tests in some
format that is independent of the tool, and for this specific problem
choose tool that is not huge. =)

This just comes down to how much we want to embrace the pytest way of doing things. We could stick to using only what is available in unittest and keep things fairly portable, or take advantage of the nice extra features that pytest provides. Swings and roundabouts[3]