Jabird,
EXT is currently owned by East Devon District Council. It is up for sale simply because the council feel that the investment in a new terminal is not something that they can undertake. There is no doubt that the airport has interested many potential bidders. LetsGo Travel have been suggested, as one of the South Wests largest independant travel agencies, however, as you have said, significant investment is likely to be required for new terminal facilities which are planned to be built by 2008.
Along with the airport comes a huge and significant amount of land for development as a retail park and I wonder how many airport operators would be willing to undertake such a development. The 'Skypark' as it is currently know, will potentially have a direct rail link and will provide much needed industrial space that Exeter has all but used up on its other sites.
I believe the bids are in to KPMG for their consideration, but all bidders have been sworn to secrecy so it will be very interesting to see who the shortlist of candidates may be. Walker Aviation, owner of Flybe, have shown no public interest, however other businesses owned by the Walker family have developed business parks in the past so who knows.....we'll have to wait and see!