They've introduced something called server progress. I'm sure you all remember the little marks we had to collect to open further and more advanced layers of astral.
Now this will all be done for the whole server - so for instance to open the new sectors - s5 to s8 - the whole server and all players will have to collect an x number of progression marks (I really don't know the exact name) and once we have done so, we will not have to use keys when going to sectors s1 to s4 but until then we will.
Also gear system is a bit silly - as until we are full epic - the best, most efficient & fastest way to gear up will be by going to sectors s2 until we have gathered enough upgraders to make blue items (it's 18 upgraders from green to blue - no doubles & with only amalgam). They will be level 65. After that we will be able to convert those items to level 66 - by purchasing an item (it will be available from the guy who normally stands beside the anvil - forgot his name) to make our 65 level gearpiece a 66 level one & also by completing a quest - you'll all find out soon enough how to do it.
The reason I said we will be doing it until we are full epic is due to the fact that the item to change gear to level 66 is a bit pricey and obviously the price increases with its quality (blue, epic, legendary, etc) so once we have epic 66 level gear, we will start going to 66 level sectors.
Apparently - sectors 1/2 are quite easy, s1 being the easiest and s2 being compared to s26 atm. The challenge starts from s3 - which allegedly is really hard but I guess we will have to see for ourselves.
I don't play on the Russian server and the information I have just shared with you, has been given to me by a very good friend of mine who happens to be Russian

so I know what I know thanks to him and you know it now too
Good luck
BB