I think Snowden went into this with his eyes open, and rather than running from the consequences of his actions he has chosen one set of consequences over another set. Did his disclosures harm the Intel community? Perhaps, but the Intel community's illegal activities do not enjoy legal or moral cover - they needed to be exposed, and some of them have been declared unconstitutional by courts of law. Without Snowden's disclosures, the courts would never have had the opportunity to exercise oversight. That is what separation of powers is about.
When we weigh the net effect of Snowden's disclosures, the number of illegal and unconstitutional activities the Intel community was engaged seems far greater than the number and volume licit activities that may have been compromised, so I would aver that Snowden's disclosures are probably salutary. It will be some time before the Intel community gets over its temper tantrum about having its illegal toys taken away. And it will probably require cooler heads than those in the current administration (which has shown an unfortunate proclivity to politicize Executive Branch agencies and use them against ideological enemies in an illegal manner) to reconsider whether Snowden is a legitimate whistleblower or a villain. I think in the long term he will be vindicated by history.
In the meantime, living as a man without a country constitutes fairly serious consequences, in my humble opinion.
[apologies for my verbosity in a culture where many are reticent to acknowledge that it is possible and even desirable to use more than 160 characters to communicate.]