No one exactly knows 10 years into the future but some 3 or 5 years from now are not that difficult to predict. What comes after depends on 1st results.
The Yanks are still trying to prolong the life of the M series rife in one way or the other. Is has been demonstrated ammo is also a very important factor in the equation, but this have been ignored several times over and by more than one country.
I don't want to give any bad news but currently the US DoD is doing every thing humanly possible to find a better round other than the 5.56mm NATO.

Trials on the "Hydra" magazine wells have been in progress to make the M series weapons capable of chewing different ammo and mags - incl 7.62mm Nato and 7.62mm X 39.
I personally have a feeling that FN will be doing some great sales stunt in the not so distant future and prove to the west that a better weapon than the M series is very real. Don't forget that NATO had always looked upon the 556 as the Holy Grail and the M/AR design is the gospel. The reality is that there are other very good weapons that have been ignored like Bofors of Sweden and Valmet of Finland, but..... (I think politics)
Also keep in mind why NATO countries switched from 7.62mm to 5.56mm in the 70's and 80's. The US had humongous amounts of 556 and a quick reconciliation of a NATO round was the number 1 priority. In case the old USSR decided to step into Germany and central Europe. The St Etienne, Sigs, HK's, SA80's, etc were all built around the 556 ammo and today we have a bunch of weapons in the field that lack punch and that's a fact!
Now it looks like armies realized that and ammo evaluation is a must before designing a new weapon. Every thing is possible and nothing surprises me but it would be foolish to see the next main player in 556 and not in bullpup config. Something to the effect of a condensed Mk19 40mm rapid fire would be useful as an attachment to the main platform (if it will be small enough).
In Eastern Europe they might put some different icing for decoration on the AK's but the fundamentals would remain - just like the Beryl or mini Beryl (AKSU).