Dell has posted the 186.12 NVIDIA driver. Posted under the new M17x, this driver is also compatible with the M1730. I have installed it and so far it is very stable. The INF file includes support for the following M1730 GPUs:
If you are interested, give it a test drive. Dell has only posted the Vista 64-bit driver, not sure if 32-bit will posted. If it is, I will update this post.