I also would like to have Framebuffer Support with the proprietary driver. There are many advantages of this:
+one driver rules on GPU (no vesafb and nvidia blob coexistence needed - everyone have such situation now).
+faster console<->X switching
+no flashing during switching
+hw acceleration (console api is simple, only few 2D functions needed, already present in X driver)
+power management (already in driver)
+non vesa modes possible like 1440x900
There is no much work for Nvidia to implement this. All hardware specific code is already in X driver. Just hooks to console driver api is needed. nvidiafb open source framebuffer driver in kernel has all required functions implemented and working.
This driver is just not compatible with nvidia blob.