Yahoo is looking fresh again!
I think this a well-thought idea to -- get more social.
Also with this move, it might push Google users to consider syncing and sharing their photos to Flickr now. Google gives 5GB for high-resolution, i.e original quality photos, Yahoo is giving 1TB, but think yahoo ads.
Any such kind of service is a lock-in ( platform level, so more control) and maybe they integrate tumblr strongly with photos? ( again a deeper lock-in to yahoo only core-products).
All this means -- they are back into Internet business.
From the past 2 days, there were enormous analysis around Yahoo, its principles were questioned, so did this all reach the board and the top management? :)