Enphase has followed
their roadmap closely and
appears to be shipping their 7th-generation inverters:

I see no big specification differences between the IQ7 and IQ7+ versus their IQ6 and IQ6+ counterparts. The IQ7 now offers 250VA maximum power versus the 240VA of the IQ6. The IQ7+ offers 295VA versus the 290VA of the IQ6+. Weight is dropped from 1.29 kg for the IQ6-series to 1.08 kg for the IQ7 series.
I assume the real benefits of the IQ7-series inverters are for Enphase, as seen in the table above. They have reduced the component count by 25% from 339 to 250. By reducing the weight they have reduced material and shipping costs. And I will assume that the move to three ASICs instead of just one both reduces total component count and allows them to minimize the total cost of these ICs. All of these things should reduce module costs. Reliability should also be improved.
I expect the IQ6-series inverters to disappear fairly quickly as Enphase needs to minimize their manufacturing costs.
Finally, Enphase has
a preliminary datasheet for the new IQ7X, which is designed for 96-cell PV modules. It is the same size and weight as the other IQ7-series inverters but it puts out up to 320VA and has a maximum DC voltage rating of 80V (instead of 60V). Because of the higher voltage, this inverter offers a slightly-higher efficiency of 97.5% versus 97.0%, at least at 240VAC output. Based on that product offering, I suppose some PV manufacturers must be bringing 96-cell modules to market. Given that, I think Enphase will need to increase the power rating of this inverter in the very near future.