The power system looks interesting. I don't know exactly how they are doing it all, but based on what I saw this is what I hope they are doing...
Relatively cheap system for running above-ground power lines (if it is pricey nobody will want to do it of course).
Multi-block transformers of various sizes that go from reasonable to expensive. For instance, something like this would be interesting... 5 sizes, Very Small (VS), Small (S), Medium (M), Large (L) and Very Large (VL). VS = 2 block, outputs 1 line at either 32 EU/T or 12 MJ/T. S = 4 blocks, 2 lines, 64/25 per line. M = 8 blocks, 4 lines, 128/50 per line. L = 16 blocks, 8 lines, 256/100 per line. VL = 32 blocks, 16 lines, 512/200 per line. This is all max output of course, the power still has to be available in the power lines to actually output the max amount. And of course all this power would be being transferred as ED power right up to the transformers and would also output from the transformers as ED with the appropriate cable if you desired (I put no numbers down for that because I have no idea how it works). It would be possible to mix/match output from a single transformer too. So an S could output 64 EU/T and 25MJ/T at the same time.
There could be special connectors for EU that allow you to force 2 or 4 outputs worth into a single line as a single pulse. So if you want, the S could put out Medium Voltage, the M could put out High, and the VL could put out Extreme. These would only take up one "line" output on the transformer but, for instance, if you had two of the 4 connector version on an L transformer it would no longer accept any more connections.
Transformers could have three versions, Send, Receive, and Send/Receive, with the Send/Receives costing a little more, encouraging users to focus on centralized power, but still giving them the option to decentralize if they like.
ED would of course have its own "local" power lines (in addition to the overhead ones) that would output from the other side of the transformer and be used to power regular ED equipment.
The power lines would need to be effectively unlimited in the amount of power they carry and have little or no loss on long runs.
I think all this would be WAY more interesting than the current solution... Tesseracts. Tesseracts are fun and useful, but they are just a tad bit OP if abused. All mods with power should offer a cheap way of handling long runs of cable with a special "transformer" required at each end to actually use the power again so the cheap cable can't be abused.... Imagine how nice it would be to connect a bunch of windmills up with tin at ~y-250, run them all into a special box that is kind of pricey, but not ridiculous, then run them down 170 to your home with cable about as cheap as tin and with no energy loss, then into another special box that returns the power to normal useable power. This concept is actually a lot like the Tesseract. Effectively the game would actually just teleport the energy from A to B, but it would only do so while A and B are connected by cable C, instead of via a frequency. AE really needs something like this too I think for moving items over long distances.