Who wants good news? I have info to pass along if anyone wants to stop complaining long enough to hear it. Seriously, asking a telephone/internet rep a question that they do not have an answer to will not help the situation - nor do they care about the 50k subs that purchased the 810... The device was over-priced, just like the 710 before it... Look for it to pop up on Groupon or some other social deal at $200 soon and grab one if you can.
Now, that said... There IS a firmware update coming - and it will include WiFi calling... I have not heard if the storage feature passed T-Mobile or not - apparently caching 3rd party info to an SD card can corrupt the data & card and create a ton of issues. T-Mobile isn't thrilled about applying their support resources to fixing a known issue with read/write issues to SD cards in this case. From what I understand though, certain Apps will have the ability to find the SD card after the update and write their data to it, thus making the 'other' space smaller by default. I'll keep everyone posted on the update timing as I have it, but for now, relax and hang on a bit. They just have to get the update through TA and then it will roll out.
And PS - The reason why this information is not being given out by support reps is that the update has NOT passed Technical Acceptance yet and is not official. Once it passes (usually takes about 6 weeks in testing and this should have been in about 2 so far) it will be posted to the support people and they will ask you to update your devices when you call in - or have data on when the OTA will happen.