I don't have a problem with their decision, and I'll certainly upgrade to pro in the next few weeks. But I also don't use Flickr for "community interaction and exploration of shared interests" - I just want to be able to create albums and put photos in them. So the storage was useful and the ostensible reason for the change (reversing the "tonal shift") doesn't entirely convince me.
But this isn't unexpected, and I think the purchase by SmugMug was a good thing. I just hope they can stop randomly losing my photos after this...
(Edit: s/convince/entirely convince/)