Someone like me could never enjoy an online "flash-based" civilization game. I've spent hours beyond hours playing civilization with 50-something civs to compete and conquer, the thought of playing the game as "casual" bothers me.
I really would like to see a Civ 5 game; people who say that things have not changed in 5 years in the field of technology really need to look things up. In 2005, high end computers used perhaps 320GB drives, many with 4-5 platters, now we can reach 500GB with merely one platter. Then we have the SSD, something that wasn't even around in 2005. In less than a couple years, $2000 32GB SSDs have drops down to $200 80GB drives.
Then we forget one of the most important things of computers, the GPU. In 2005, the Radeon X1000s and nVidia 7000 series reigned supreme, but they were subpar compared to nVidia's next gen 8000 series that literally blew away the previous DX9-based 7000 series. Now we have the likes of the Radeon R800 (5000 series), packing DX11, capable of doubling the performance of the previous powerhouses as the Radeon R700 and nVidia GT200.
Then the processor, how times have changed. 2005 was just a year away from the likes of Intel's Conroe processor (The Core 2 Duo), but we still had to deal with such an awful set of Intel chips, Netburst (AKA: Pentium 4/D) were totally owned by AMDs offerings, even with clocks that weren't as high. Since then, AMD has provided us with highly overclockable Phenom II processors and Intel has given us the likes of the Core i7/i5/i3/iWhatever; my i7 gives me 8 virtual cores to play around with @ 3.8GHz clockspeed.
Things have changed since then technology-wise, I remember sporting 1GB of RAM back in 2005, now I use that much and more on my current rig 24/7, my computer now sports 6GB of RAM, and even now I'm finding that too little for my needs.
Civ5 with larger maps would be nice. Sure could use 512x512 maps that use less than 6GB of RAM would be nice. :|