While I agree that there is probably not very much the Council can do to stop this, they could be proactive in voicing concerns about the loss of the Speedway and attempting to influence the developer as much as possible.
Hopefully the development of houses will be the issue, and locals will object as strongly as they can, but even then, isn't this land already identified for housing many years ago?
Not that far across as I understand it, only up to Haydon Wick/Abbey Meads, but they're past that already....
Policy R8 of the Revised Deposit Draf of the Swindon Borough Local Plan to 2011 applies to the Blunsdon Stadium area:
"7.6.4 The site currently occupied by the
Abbey Stadium is safeguarded for leisure
development uses. Swindon Speedway
and Greyhound Racing Promotions
currently occupy the Abbey Stadium and
form an important part of the character and
recreational life of the town. The site
adjoins the Northern Development Area
and in order to safeguard provision,
possibilities for more intensive leisure use
of the site, by way of redevelopment, would
be permitted provided that the development
complies with other relevant policies of the
plan."
"Other relevant policies of the plan" would presumably allow housing development on part of the site (as it is considered to be "brownfield") if it meant that better leisure facilities could be provided. AKA 'enabling development'.
The land between the stadium and the existing houses at Abbey Meads (next to Motorola) comes under Policy E1/19 as a Key Employment Area and is very unlikely to be allowed to have houses built on it.