1. The court only found that a single program exposed by Snowden was illegal. Snowden released a bunch of other information that was a violation of the NDA he signed when he was given a security clearance.
2. Even if all the information he disclosed revealed illegal activity, Snowden's actions make him ineligible for whistleblower protection. Whistleblower protection for the intelligence community[1] is only provided if a person follows the proper procedure to securely notify their Inspector General and/or Congress. Since he's not automatically protected, it would take Congress or the President to decide to offer him protection. Snowden (allegedly) did not even attempt to notify the proper authorities before going public with the information, so not only is he ineligible, it's not likely that anyone will take pity on him.
3. There's a chance that this ruling won't stick as the legal system chugs along and a few more judges look at it, and even if they were willing to help Snowden, nobody in Congress is going to take action until there is some permanence with the ruling. IANAL, but I think this would be decided if the Supreme Court either decides to decline or hear the case. If it's declined, then it's pretty much final. If they decide to hear the case, then it could be another year or so before they make a decision.
[1] IC whistleblower protection is a little different than standard whistleblower protection: https://en.wikipedia.org/wiki/Intelligence_Community_Whistle...