I agree with you - PocketHAL on desktop is just for development, it does not make sense to create real game/application with it. There is plenty other hardware abstraction layers on desktop, like DirectX or OpenGL which is relatively easy to use.
PocketHAL game on Desktop will look awful because of 16bit color depth. It looks awful enough on Pocket PC, but there we do not have choice. And changing color depth to 24 or 32 bits in PocketHAL does not make sense because all graphics algorithms created with PocketHAL in mind would cease to work on Pocket PCs... Also this will make rendering on Pocket PCs slower.
If someone is going to develop modern game for desktop, even as simple as Tetris, it is better to use 3D hardware from start, because it gives you almost unlimited freedom in using modern lighting/texturing techniques.
Regarding speed - World of Warcraft runs nice on my office computer with builtin GMA950 video (it gives about 25 fps there, but I played for month without any trouble)! You can safely assume that OpenGL will give you 100fps in any 2D-looking graphics on any practical machine.
So please do not waste your efforts on "providing DirectX resolutions" via PocketHAL. This is useless and will lead in best case to very bad-looking ancient games ported back from Pocket PCs.
BTW I speak as game developer with experience - you can look at
the game was created in late 2004 with "modern" features, like 3D shaders support, 3D sound, force feedback controllers support, etc. It took about 4 months of work in the team of 4. Later the shaders support (which made game Microsoft rendering context semifinalist) was turned off because office computers 3 years ago were not fast enough for shaders. Also the game was ported to Mac OSX without significant efforts (changed 3D HAL from DirectX to OpenGL and DirectSound to OpenAL).
So any game should be prepared for changing its HAL. My advice to anyone who wants to create modern game for Desktop is sticking with OpenGL + OpenAL and your game will run on both PCs and Macs without significant efforts from your side.