I'll agree that lack of all-or-nothing marking of multiple response questions is a strange omission. There is a third-party question type that does this, but it has not yet been updated for Moodle 2.0, I think.
In that area, the Common Cartridge QTI subset will probably be useful. Most VLEs will want to have all the question types it defines covered. The other notable omission in Moodle is a regular expression question type.
In terms of where Moodle quiz development is at, currently I am working on a lot of big changes behind the scenes Development:Question_Engine_2. That was developed in-house at the Open University, and was released onto our live servers a couple of weeks ago. However, the plan was always to add it to standard Moodle, and that is what I am working on now. That should be done by March next year, which means it should go into Moodle 2.1. Martin D. is currently talking about Moodle 2.0 in July next year. Be very sceptical about that data (it is a guesstimate, not a deadline), but hopefully that means we should see a finished 2.1 within a year.
Because of all that behind-the-scenes work, I have been very reluctant to extend the range of question types in Moodle, so once the big change is over, adding more question types will be a long-overdue priority. And I am looking to this forum to lead the debate about which question types we most need. Depending on timing, those question types will either go into Moodle 2.1 or 2.2. Others will only be available as third-party plugins.
The other thing that is going on at the OU is a whole lot of new-feature work at the same time as we move from Moodle 1.9 to Moodle 2.0 (http://learn.open.ac.uk/mod/oublog/view.php?user=27287). One part of that is that we are having a whole lot of new question types made, including things like drag and drop to fill in the gaps in sentences. Some of those types will be good candidates to go into the standard Moodle release. As I say, we need to have a discussion about which.