My question is. Say I had 25,000 to drop on one of these things. Is there anything out there right now to take full advantage of it? Do they have ultra BluRay players coming out?
First of all, the initial prices are not representative and will drop very quickly once there is a market demand and sufficient competition.
Will there be a new Ultra-HD/4K Blu-ray format? You bet!
Is there any content today for home use? Not really, but it will become available soon. How soon? Perhaps we will know better next week, once CES starts.

Could you take advantage of the 4K resolution today if you had an Ultra HD display?
Actually yes! At least in two ways:
1. You can view photos! Most digital cameras today have more than 4 megapixels.
2. You can upconvert HD to Ultra HD. (It's like upconverting SD to HD.) You wouldn't get true Ultra-HD, but it would improve the picture.