Apple won't make a DV or digital camera because there's nothing to gain by entering the current market....even if they add a 2.5GB harddrive.
They're not going to add WiFi to iPods that only last 8 hour as they are. People buy it because its simple to use, and because they look nice. A downside is the battery life, but if the battery life dropped even more, I think people would be reluctant to buy one. Yes, you can turn WiFi off, but how much of the battery would you drain if someone were to actually try moving 1GB worth of pictures to their computer wirelessly?
They're not going to use the Seagate products whatsoever unless they really need to due to production issues extending towards the end of the year. Just because someone produces something, doesn't mean that Apple is automatically involved. It would be funny if they had 3 manufacturers making HDDs for their iPods just because these companies made small HDDs.
The iPods seem slow enough, so with a HDD of 3200rpm instead of of 4800rpm, they'll be even slower than before.
How reliable are these HDD's, and how do they stand up to being shaken and such? Oh wait, nobody knows yet.
A 2.5GB HDD won't be too much cheaper than the 4GB HDDs made by Hitachi, like someone mentioned already. If Apple gets the 2.5GB's for $30 cheaper (say $70 instead of $100), all Apple can do is sell them for a bit cheaper. If they actually sold a 4GB Apple Mini for $249 and another 2.5GB model for $219 or something, it really won't work. If they sell it for cheaper than that, they'll make less money on each iPod mini than before.