I agree Neil that bandwidth is the issue, and current tech might indicate that 24MP x 8fps isn't quite feasible at this time.
So, would the world accept a 16MP DX camera at $1800? I think it needs some other standout feature, like 10fps. Then it would be positioned similarly to the D4 in that it's unique in its performance, and specific to a limited group. Would that group be big enough to support such a camera? Of course I have no idea, but personally I think I'd prefer 24MP*8fps over 16MP*10fps (I'd seriously consider the latter though).