Lets face it...whoever wins the civil war has the Dragonbord on his side.
The Dragonborn,who knows and can use a lot of combat specific shouts,the dragonborn,who can summon in battle Odahviing and Durnhevir.Furthermore the Dragonborn can become leader of the mages of the College,the listener and leader of the DB,Master of the thieves guild,and Harbringer of some of the strongest warriors of Skyrim,the companions.
Should the dragonborn go ahead serving for the cause he has chosen prior to the civil war and follow the Legion or the Stormcloacks,he would help fighting and defeating the thalmors,no matters who wins the civil war.
Am i right?

While I'd rather see Tamriel be divided into nations again instead of the one big empire. It looks like what beth has planned is an empire collapse followed by the rise of a new "Septim"ish figure.

Which is exactly what's gonna go down in probably the last DLC. We already have an Enantiomorphic event in the end of the Civil War that the Dragonborn takes part in (or heck, technically the entire civil war is an enantiomorphic event).

Regardless of the outcome of the civil war, the Empire has already collapsed. What remains is an attempt to hang on to past glory. But, yeah, it seems very much like that is the long term plan of Bethesda. I'm not so sure about the new Septim, though.

Possibly. I'm not convinced. Forging a new Empire is not a small task. Even if the DLC is of expansion pack scope, I'd still consider it too small. More like an entire game dedicated to the war on the Thalmor, followed by a game where a new Empire is initiated.

Idon't think so...everyone is hyped about the future of tamriel.It's almost sure that when the secon great war will take place,the Dragonborn will still be alive,its a matter of few yeas in my opinion,and if they choose to make a whole game about the war,it would be very stupid and anticlimatic,since there would still be the dragonborn around.

Not necessarily. They could say the the dragonborn mysteriously disappeared after the events of Skyrim, eg got tired of fighting and went on to explore some Oblivion plane and never came back or was killed while exploring some Dwemer ruin, perhaps he/she retired permanently, perhaps joined the other Graybeards? The possibilities are endless...

It is possible that Dovahkiin kills Paarturnax and the greybeards hates him,but i see your point.

Imagine this: the Dovahkiin kills Paarturnax but then sincerely feels guilty and asks for forgiveness by the greybeards. They hate him initially but after a while they realize that the Dovahkiin is too much of a potential risk/danger to be allowed to roam free (who knows what else he/she might do???) and allow him/her to retire in the monastery and spend the rest of his/her life in meditation in the way of the voice.

If they do do a game based around a 2nd great war with the Dragonborn still alive and kicking butt, will s/he have all the shouts already or will s/he have to go searching for them all over again?

I think the Dragonborn's story is over and done with and s/he is either dead and buried, or gone on his/hers way or his/hers soul has finally been collected by one of the Daedric prince's.

Lets face it....the next game will probably be set 100-200 years after the events of Skyrim.

Well thats not so sure...yeah,there are 200 years between TES4 and TES5,but not so many between ARENA and OBLIVION,since uriel septim VII is present in each of this games. (3E 389-3E 433)

(sorry for double post,cant do multiquote)

I dont think so...the thalmors want to undo Nirn and the mankind...i'm sure that the dragonborn won't stand aside while the Dominion tries to destroy the same world that he has just saved from Alduin.

Awwww come on let me have THIS ONE. I did say PROBABLY.....

lol
The fact is that i want my dragonborn to kick craploads of Thalmors arses and save the world again before his time ends.