OP, looks pretty good to me.
4890 should do for anything you care to run for a while - a little later you might want to buy another for dual card rig. Alternatively see what Nvidia and ATI come up with in the next 6 months or so. Don't be too quick to buy into new technology. The new crop of ATI cards look good but what DX11 games are available now? Let someone else do all the debugging. then buy into the next generation, maybe.
Never save money on a case - get the one you really want. You will be looking at it day in and day out for years to come. Since a case can last up to 10 years it becomes one of the cheapest components of your system whatever you pay for it.
Think VERY carefully about whether to go h50 and water cooling. When I looked at it, the thing only had a two year warranty. Do yoy want to run it for more than two years? Do you want the constant worry about cpu cooler component failure and leakage. Water and electricity don't mix! If you run a car think about leaky seals and pump failures and gaskets going. Then translate that experience into a PC.
The only drive failure I ever had at home was a samsung. Lots of people are unhappy with Samsung. When Samsungs are working properly they are fast and quiet and quite cheap though.
Know why you chose those components in the first place and don't be afraid to stick to your guns. It is not a case of good and bad components, it is a case of excellent components and slightly more/less suitable components.