Hi! A colleague of mine and I are both planning to take it in the next week or so and she'll be writing a blog post about our experience. (I haven't scheduled my date yet; I'm not sure whether she's scheduled hers.)
I'm expecting it to be very similar to the GMAT Online experience—you'll have to use an online whiteboard (the same one), so you'll obviously want to practice with that extensively.
https://www.youtube.com/watch?v=GPpsawfpM_EWe have more videos up now on our YouTube channel and we're about to post two more (probably tomorrow) that show multiple teachers solving Quant and Verbal problems using the online whiteboard, so check those out for ideas.
Other than the whiteboard, the EA test experience should be very similar to the real thing (if not essentially identical). It's always been the case that the EA is 1.5 hours with no break, and that's how it will be online as well. But we'll let you know for sure after we take it.
So just make sure to do your practice problems and practice tests with the online whiteboard from now on. You said that you're taking it at the end of this month, so you have a solid several weeks to get used to it—if you practice, you'll be fine.