The test measures a player's current brain activity versus a baseline that was established prior to the season. Michael Vick is reportedly symptom free, but the fact that he hasn't reached his baseline from earlier in the season is obviously concerning and you have to wonder whether he can or even should play again this season.
There's no justification for risking Vick's health in a season that's basically lost. The Eagles won't have a choice if he doesn't pass this test, but even if he does you do have question whether it would be worth it?
For this week at least, the failed test means that Nick Foles will make his 3rd straight start. Last week he was on Monday night football and this week he'll get the national stage again on Sunday night football in Dallas against the Cowboys. He'll be without his top WR, RB and at least according to recent reports will again have a reshuffled offensive line.
Like I've said before, Foles hasn't looked good this year, but for him to succeed in the face of all this would have been some kind of miracle. So while we're getting what we want as far as playing time for Foles, I really don't think we're getting to see whether he can actually play or not.