Question: I haven't been able to find where it's confirmed the Third Birthday is going to be downloadable. Could you provide me with a link?
Another question: How many of those games were released worldwide on the PSN, as you'll find different countries have different PSNs and different games?
Now, for my response. I don't hate the GO, in fact, if it was able to play UMDs, I would've bought one, without a second thought. But because it doesn't, it made it a bad decision, putting all of my eggs into the digital download basket, when for cheaper, I could get something that could play both digital and UMDs.
And I fail to see how a logo at the bottom of a page is proof that there will be a digital release at launch. There has been no evidence to suggest BbS's release onto the PSN at launch, so no evidence=/=it must be on there. Note how I'm saying at launch. No doubt they'll eventually release it onto there(Unless it's like the Final Fantasy PSP games(minus Dissidia) and the Star Ocean PSP games, both Square Enix series not released on the PSN) but with the lack of evidence we have, I doubt it will be on the 7th-10th of September.
As for the PSP Go sales numbers, you may want to read this article. Essentially, in Japan, the GO has sold less in this year than the regular PSP does weekly.
PSP Go sales in the toilet - PC World
I'm expecting another Dissidia here. No digital release until almost two years after the physical release.