For those following this item:  there was a previous feedback item that talk around this: 

It has been 2 years since that feedback item and I forgot about it until seeing this item.  But having to do this workaround interrupts general user flow to do it or go through TS directly to change them.  

I believe its a big usability concern.

http://feedback.telerik.com/Project/161/Feedback/Details/41122-cannot-get-to-ts-test-properties-in-vs-2012

Provided by Pavel Kotsev
Here is a workaround step by step:

1) Open your solution.
2) From the Solution Explorer right click the solution item.
3) Select Add/New Item
4) Do not click on any of the available items, instead type in the text box 'TestList.vsmdi' or any other item name that ends with '.vsmdi'. Just make sure not to click on any item as it would overwrite your input.
5) Find 'Solution Items' sub folder directly under your solution
6) Double click TestList.vsmdi - this will bring up the 'Test List Editor'
7) Select one of your tests from the 'Test List Editor' right click it and select properties.
8) In the properties pane find all properties of Test Studio tests.