1st I hope that they continue the support of standard HDD's.

2nd I hope they move to 3.5in.

3rd I hope they have full support for external drives over the USB 3.0.

Finally, I hope they offer 500GB and 1TB options.

It's going to be 500gb at the very least, any less doesn't make any sense price/gb wise anymore. I can see them adding 16gb or 32gb off flash memory aswell.

500GB for the premium and 32gb flash memory for the tard pack.

I think they should only have a $499 1TB model at launch. This will probably incur a cost no more then $40 per system, I think as a marketing tool having 1TB makes the system sound very next-gen and having only 1 SKU makes for effective/simplified marketing.

Maybe introduce smaller flash models once they're ready to introduce the system to the mass with its first price cut.

I'd rather have a lower capacity SSD than an enormous HDD. Speed over size!

Edit: 12G Flash isn't what I would deem a "lower capacity SSD", that would be something like a 120GB SSD. It would suffice as a start.

We think alike mister! High five! ;)

Just like with the PS3, the OS on the PS4 will without a doubt be stored on an internalf flash storage. So SSDs won't accelerate the system like they do on PCs. There's nothing wrong with games stored on an HDD, Loading times aren't significantly longer and it's just a lot cheaper. It's only important to have your OS on an SSD, which is, as I said, already the case with the PS3. 

There is no need for an SSD inside the PS4. Just try to put a SSD inside a PS3. It's possible. But you won't notice it. Loading times are somewhat faster, but only by 5 - 10 %.

don't care so long as it is standard and expandable like the ps3.

I agree with you on needing to have the OS on a flash storage. However, smaller loading times is a high priority for me and as such I would rather have an SSD.

Various benchmarks have shown that games on the PS3 have anything from very slightly shorter to signifcantly shorter loading times. And this is on a console that was never built, or at least optimized to work with such hardware. PS4 will surely be prepared to take advantage of all the benefits that SSD's provide.

Anything less than that and everyone would see it as a serious step back. So that setup at the very least is what we're all expecting I'd say.