Apparently, the program worked wonderfully, and they got a lot of useful intelligence out of it. However, word somehow got out that German prisoners there were being treated like royalty while the British public starved. There was outrage in Parliament, and Churchill ordered the program shut down.
British intelligence pretended to follow Churchill's orders, but actually continued the program in secret. The information they were getting was just too useful. They just stopped telling Churchill about it.
I expect something similar might happen here. To the public's knowledge, to most of Congress, and maybe even to Obama, the program might appear to be shut down. But it'll either continue wholesale or morph in to something else that's effectively the same (or even worse).
Unfortunately, there really is no way to verify the words of these spy agencies. Virtually no one has the clearance to go inside their datacenters and check. Now they'll probably just be a lot more careful about keeping what they do secret.
Remember that the NSA is far from the only secret agency in the US. For a long time its very existence was denied. The running joke in Washington was that "NSA" stood for "No Such Agency". Eventually, its existence was confirmed. But there are probably dozens if not hundreds of other secret agencies that operate under the so-called "black budget" that Congress authorizes. Who knows what they do? Something like PRISM could easily migrate to one or more of them.