Yakuza 1, 2, 3, 4 and Dead Souls are no where near the length of Yakuza 5. Yakuza 5 is about Yakuza 2 and 3 combined in terms of content and the story is 30 hours alone.
So I doubt its a foregone conclusion, especially as SEGA Europe's president specifically said the game is too expensive to localise.
I thought Yakuza was pretty long anyway? I guess not.
Depends how much dialogue to story missions there are though. Given that SEGA have a set fanbase that will buy Yakuza no matter what, they'll have to do the maths to see whether it's worth it, and tell the fans whether it's possible to do or not.
In comparison, Valkyria Chronicles 3 has a lot of talking and text as well, probably longer than the first game even, given that you have 20 Chapters plus a few side missions to boot.
In my personal opinion, I think Yakuza sells well enough to warrant a text localisation for SEGA, but Valkyria Chronicles probably wouldn't despite the PSP being the easier way to make a profit, since the PSP doesn't make enough sales and is irrelevant vs the PS3.