A Question regarding micro 4/3rds
No real tele-converters yet (the one between body and lens).
An online interview bij Onfoto.ru suggest they might be on their way:
Dimitri Kroupski: Do you have plans about a teleconverter for the Micro 4/3?
Toshiyuki Terada (from Olympus): Yes, we had the same kind of demands before, and we like to provide a total system, so we need teleconverters, sure.
( http://www.onfoto.ru/event/Photokina-2012/1980.html )
A 2x tele combined with the 75 1.8 sounds like a great idea to me, although a look at the prices of 'normal 4/3' teleconverters from Oly does indicate a high price (400+ euro). At that price, combined with the 900 euro 75 mm, I would reconsider getting the 75-300 mm zoom...
As for spoiling good lenses; a good lens with a good converter can outperform zooms, and it will be lighter and smaller than a zoom or 2 long primes (size/weight being part of the m43 allure).