Joking aside, gunpowder driven small arms is pretty mature tech at this point. I don't think you are going to see anything put small incremental tweaks until we completely change to something else. Something as revolutionary as brass cartridges was. Dunno what that'll look like, but it'll be pretty cool.
If, however, you want to know whether the government or industry drive development in this sector better, I invite you to look at the period between 1970 or so and 2004, when we went from the M16 to the M16A2, or the CAR-15 to the M4. The G3 went to the HK33 and the MP5. The FAL went to ....The FAL I guess. We did get the AUG and P90 in there. Then compare that with the small arms that have entered the market from 2004 until now. SCAR, AR-lego kits, Tavor, MDR, RDB, RFB, ACR, Scorpion EVO 3, hell who knows how many others are floating around gunbroker.
Now what happened around 2004?