We have just discovered that the final day of the 2 wk trip we are planning is Holi. We plan to be in Delhi, Agra and Rajasthan (Jaipur, Jodhpur, Udaipur, Rathambore park). We could organize our itinerary to be in any of these cities on Holi; or we could leave a day early to avoid it. Will it be a fantastic experience, or crowded and scary?

It is not a good idea to be out on the road at this time -- crowded and scary is pretty accurate in the cities. That said, Ranthambore Park should not be a problem then, and in the cities if you are in a hotel there isn't really any problem.
Essentially, it's not a good day to be traveling around.

When does Holi fall in 2008?

We were in Goa during Holi a few years ago and it was completely safe, however i have heard that being in the big cities it can become quite scary and dangerous at times, and it is best for tourists to stay away...Now that is only what i read.

Having said that...i never had so much fun in my life as when we celebrated Holi in Goa..

Holi is Mar.22 in 2008