We have a VS2010 Beta 2 DSL Project , We can build, deploy and test on our Development machines and all is well i.e When we go to 'Add New Item' we can select our DSL
When it comes to giving the VSIX to someone else to try the ONLY way that they can see the associated Project Item is if they build the DSL Project on their machine, they do not need to F5, it is just a simple Build Solution and then voila they can see it.
Is this a bug or user error?
You might want to update your bits to the RC version, which are now shipping in the VS Visualization & Modeling SDK at http://www.microsoft.com/downloads/details.aspx?FamilyID=cd443b01-d657-4f8b-b5b8-29f1e3e2c424&displaylang=en