I've played (and completed) only FFVII, FFVIII and FFIX. By one side, I'm sooo happy 'cause of the FFVII Compilation that it makes it worthy to wait for spin-offs of great games.
By another, I've not seen/used any product of the FFVII Compilation which makes me really sad... I mean, if they do the spin offs only for mobiles phones in Japan or bring some titles to the newest platforms(such as PSP) it might be...frustrating? I don't think that's the word. Let's say, it wouldn't be good
PS: Yes, I'm still waiting for the Spanish release of AC, what's wrong? xD I've already seen the cover of the special edition in Spanish, so official date: it's coming in November.
CONCLUSION: Spin-off for some games could be good!
For FFVIII for example, the Sorceress War and so on. For FFIX... I guess a new enemy/adventure should be created. (Am I the only one who found Quina funny?? xD lol )