It will not operate again this season.
We do not know if the prohibition notice is still in effect, however I believe it won't be - that is to say that Merlin will have satisfied the HSE that it can be run without causing another collision (that was probably proven when we saw the cars going round a few days later). That therefore leaves the decision in the hands of the park, who have seemingly written it off for this season.
It's reopening is far more complicated than most of you seem to comprehend. It is possible that they still haven't decided what to do, however a design review is in progress with Gerstlauer. I personally believe it will not re-open as The Smiler we know, be that a gimmicky change to the trains and/or possibly simple rename....or something else. The popularity of The Smiler as we knew it re-opening is unlikely to be worth it from a business point-of-view. Despite some of the delusional comments on here, people aren't staying away from the park because it's closed and it certainly would be the least popular rollercoaster in the park if it were to reopen.