We need some level of Sharing in OmniFocus for situations just like you mentioned. I don't feel that OmniPlan is the right sort of app for this level of engagement. Why do I need omniplan if I just want to make sure my wife and I are in sync with our ToDo's?
We've been using zenbelists for our shared Tasks as of late since I rely of collaborative Task Work. We may switch over to Evernote and Egretlist though as I am starting to like the fidelity of our options with it.
FWIW I've been on a quest to see better collaborative tools within OmniFocus, but because of the nature of my work, I've since moved on from using it for any real work stuff. Internally @ the office we've migrated to an OpenSource Task Management tool called TaskFreak which allows us to Share and Collaborate in the way that I want to work. Each Project and Task is permissions based and so far has been doing the job I wish I could have done in OF.
I find that most people on the OG site don't find much value in Collaborative work within OF, and will always tell you to use OmniPlan...but in reality, OP isn't the solution as there are no Sharing Tools within it.
I hope this changes soon as I really like OF, but I am not finding it to be all that it can be for the way I work.
Don't get me wrong...it's a wonderful app if you are into just keeping track of the things you and only you need to do...but as someone with a rather layered life who works with others quite a bit, I really need something that is fluid and allows me to share milestones and tasks with others.
Oh well, as the mantra goes, "Use what works, and use it well."
For what it's worth i've started an online Feature list:
http://www.evernote.com/pub/policarp...usenhancements
Let me know if you are interested in collaborating and I'll send you access to the Notebook.