I've been having a think, I doubt it will happen but I would like to see Alton Towers cut their losses and open The Smiler as soon as they possibly can. If that means next week then open it next week. Of course it all depends on whether the prohibition notice is in place and if they have complied with any improvement notices.
It's almost been two months since the incident now and the performance of Alton Towers has been impacted severely. It is obvious that they will get more bad press whenever they do decide to re-open it; whether that be this year, next year or in three years. More bad press in the next few weeks won't have a significant impact on already low guest numbers. Bad press around the start of next season, just when they need to be pushing to get people back to the park, would (in my opinion) have more of a negative impact on Alton Towers.
Towers and Merlin have had the chance to review all procedures on The Smiler, any new procedures can be implemented and staff be trained. If new CCTV or sensors needed to be installed then there has been time to do this and if it still needs completing then it shouldn't take too long. Videos/annoucements can be edited as necessary like they have done on Oblivion, that did not take long.
They would only have three trains but with guest numbers so low I think it would be able to cope until the end of the season. Then come the closed season they can look into getting a new train or two and carry out a slight 're-theme' to make sure changes made result in a cohesive theme.
As I said I do not think it is something Merlin will consider. They will deem it as insensitive to re-open it at this stage.
I say all this on the assumption that Merlin/Towers now know exactly what happened and caused the incident. I think they more than likely are but if not they definitely can't re-open it yet.