We all know the Soyuz to fly in october will be an improved version (called Soyuz TMA) which will enable tall and short astronauts to fly and also remove the third cosmonaut from flying tasks.
My friend Bart Hendrickx (who knows amazingly well russian language and is a first hand space nut got this info:

Soyuz TMA is indeed a minor modification of the TM model. It can accommodate
taller astronauts and its soft landing system has been slightly improved. In
fact, it's surprising that it was given a new designator (the "A" apparently
standing for "anthropometric"). There were much more basic differences
between say Soyuz-11 and Soyuz-12 without the designator changing.

According to a recent report on the Novosti Kosmonavtiki on-line forum RKK
Energia is already looking beyond Soyuz TMA and planning models that *do*
incorporate some more basic changes. Those changes will be made in two
stages. There will be an intermediate version called Soyuz TMS and a final
version called Soyuz TMM.

Soyuz TMS will among other things have improved computers, two additional
braking engines in its Approach and Docking engine system for safer dockings
and its parachutes will be deployed at lower altitude "to increase landing
accuracy with a view to shifting landings to Russian territory".

Soyuz TMM will have similar modifications plus a Regul satellite data relay
system and a new Kurs-MM rendezvous system. Perhaps more significantly, it
will be able to stay in space for up to 380 days, which will significantly
reduce the number of Soyuz exchange flights (bad news for aspiring space
tourists...). TMM will also have just a single computer, which will be in
the descent module (now there is one in the descent module and another one
in the instrument module). There are no indications when TMS and TMM will
actually fly.

The same forum also mentions a vehicle called Progress MM. I'm not sure if
this is a typing error or if it indeed refers to an improved model of
Progress M(1). All the details about these new vehicles are said to be in
the massive second volume of the RKK Energiya history.

Bart Hendrickx

Raoul