Actually, some historians do support this migration from east to west.
Ranbir Tomar, had provided one link earlier (if you read the chapter on UP):
http://www.tri-murti.com/ancientindi...istory/ch4.htm (westward migration),
In addition, this inagural address by BB Lal at the 19th International Conference on South Asian Archaeology, held at University of Bologna, Ravenna, Italy on July 2-6, 2007 also talk about westward migration out of India:
http://www.archaeologyonline.net/art...paradigms.html
Specific quote from the above talk:
"Ayu migrated eastwards. His (people) are the Kuru-Pancalas and the Kasi-Videhas. This is the Ayava (migration). Amavasu migrated westwards. His (people) are the Ghandhari, Parsu and Aratta. This is the Amavasu (migration).
According to the correct translation, there was no movement of the Aryan people from anywhere in the north-west. On the other hand, the evidence indicates that it was from an intermediary point that some of the Aryan tribes went eastwards and other westwards. This would be clear from the map that follows (Fig. 1)."
In addition try to read Talageri's newer book (from 2008):
http://www.scribd.com/doc/8116734/Talageri
So there is discussion on westward migration, both Talageri and B B Lal contend movement did take place from somewhere near Punjab/Haryana after battle of 10 kings, with actual quotes from the text on both occasion. It also ties in with Natthan Singh's contention, that there was an emigration out in very ancient times followed by immigration in (I actually thought that it never made sense but now it does)
Back in 2003, Sivaji Singh delivered a talk which he ended by saying that more research in coming years will be about people moving west out of India, which I had posted earlier:
http://www.indicstudies.us/History/C...in, 2003.pdf
However, it is a different matter that question of Uttarkurus is not discussed by any or as a matter of fact by anybody in detail, except for what Rajpal ji had provided or sometimes one will get some mention here and there. Dahiya does discuss it in his book but I think he may relying on the same source that has been quoted in this thread early on. It will also have to account for chronology of Ved, viz a viz, Harappans, Ramayan and MBh. That will be a new aadhyay.