Just wanted to note a couple of points...
1) I totally respect your comments about VS, we're improving many aspects of VS and performance and robustness are certainly part of that.
2) Tests can be as small as methods, so, the comment about 10,000 is from the standpoint that we’ve tried to make the environment very usable even for large numbers of tests.
3) You can load tests without projects and solutions. If you are just wanting to ‘manage and execute’ tests, projects and solution are optional.
Hope this helps clarify the comment…