Austin Bay posts on this possible development at his blog.
I also do not believe the denials. That said, we need to ask ourselves if Ethiopia can project sufficient power by itself or in conjunction with other African nations (like Kenya) to roll back the ICU advances in Somalia. That answer has to be no, at least from where I sit.
According the Naval Institute Guide to World Military Aviation (1997-1998), the total transport assets of Ethiopia and Kenya are: 10 An-12 "Cub" transports (a Russian-built variant of the C-130), 6 De Havilland Canada DHC-5s, and 3 De Havilland Canada Dash 8-100s.
That is just not able to provide sufficient combat power to re-take Mogadishu from the ICU (which will probably have assistance from Eritrea). Pushing the ICU out will require assistance from a major power, either France (which has bases in Djibouti) or the USA (which can send a mix of 82nd Airborne and MEUs anywhere in the world).
This time, we need to get Somalia right.