I don't mean to rehash what I know is a old issue, but as I'm digging into OF, I got bit by this behavior. I searched the forums, and read some old threads and understand that there is a GTD convention at play here:
http://forums.omnigroup.com/showpost...62&postcount=2
"the Religion of GTD permits only one next action per project, regardless of the sequential or parallel setting."
It seems that people new to OF will continue to be confused as to why all items in a parallel project aren't "Next" (like the behavior seen for single action lists/Buckets).
I know one has to guard against feature creep, but it seems a simple pref would be warranted that reads (with radio button choice):
For Parallel projects:
First Item in list is considered as Next
All items are considered as Next
I don't view lots of choices in prefs a bad thing - to me they really aren't the same thing as feature bloat.
The engineering is already done, because this is exactly how buckets behave now...
-P