With the announcement of DCS World, as add-on developers, we really need a good SDK, like CryENGINE:
http://www.crytek.com/sites/default/files/CryENGINE_FreeSDK_3_4Update.mov
I think supporting 64 bit, DirectX 11 and Multi CPU - GPU by EDGE is necessary in near future (it could add lots of potentials, making life easier for 3rd party developers)!
It'd be great if everything in DCS World was perfect, Su-25T (6DoF, clickable cockpit with dynamic shadows), and even the map (Nevada)!
As a loyal fan, I'd like high fidelity aircraft, but also like high fidelity terrain (high resolution).