I have an account with Smugmug, been having it for about 10 years now. I was often asked why I didn't switch to ... Flickr, because of the mass amount of storage there for free (1 terrabyte!). I would look into it, although with some doubts due to the problems Yahoo has experienced with security. But basically it felt like it came down between Flickr or remaining with Smugmug (of whom I have been very satisfied, even though I realise Flickr has a higher ranking when it comes to most frequently visited websites)
Now that both options fall under the same umbrella, this changes a lot of course...
I doubt Smugmug won't change anything. In an article I found on the website of USA Today (I googled a bit after reading your post about the purchase of Flickr by Smugmug) it said Smugmug wants to revamp Flickr a bit to make it function better.
Maybe Flickr will eventually be "absorbed" by Smugmug? I mean, why would they decide to keep both services separated and cause interior competition?
I wonder too if anything about the functionality of Flickr and its ToS will change in the near future. I had already made a comparison sheet but I guess that this is no longer relevant if Smugmug indeed makes even minor changes.
That said, I have always been very satisfied with Smugmug, even considered having an account with both services... If they will now run Flickr, then I will say I have more faith in them than in Yahoo to run a reliable service in the long term. Smugmug's support team is fabulous too!