Well there are a gazillion new products but if you mean an actual improvement rather than a 1000 different flavors there are limits. There are many new good new IEMs but both single BA and multi BAs are kind of stuck - on the neutrality front the ER4 is still the one to beat despite a good fight from the hifimans and fishers, and on the multi driver BA front the new offerings - ue900 etc... - remain at the level where they compete with offerings from a few years ago (w4, se535). So no breakthrough but many people are making new products and trying new things, especially:
1. Hybrid dynamic and balanced armature IEMs
2. Phase technologies (JH's freqphase)
3. External crossovers
4. Custom IEMs turned into universals, especially those with a gazillion drivers (334, the new heir)
5. Big "subwoofer" drivers (okay, maybe not a big thing but those Fitear 335DW dual woofers leave quite an impression!)
I think we might we might be an experimentation stage, people trying are to find the next big thing. UE (UE900, triple bore design) and AKG (K3003 hybrid) have tried and not, in my view, entirely suceeded, but Westone and Shure have been quiet. That might mean a chance for the smaller companies - Fitear, Hier, etc... But then again, I remember the HD650/K701/DT880 triad lasting for at least 4-5 years before the HD800, T1, LCD2/3 and HE-series came along and gave us what I think most consider another level of performance, so maybe we are also waiting in the IEM field.
Edit, more thoughts: To move on from the HD650/K701/DT880 triad, designers had to go to new technologies (HD800 - ring driver, T1 Tesla) or seriously improve overlooked technologies (HE-series, LCD-series - planar magnetic). Could we be waiting for the next big thing in IEMs?