Personally, and I've posted in similar threads before, I am against a 'system wide' chat, I could possibly be convinced concerning 'station chat' but for me that would need to either be 'off' by default or need to be 'opened' on a pilot to pilot basis. The problem with the 'don't want it, don't use it' argument is that if, for example, 'station chat' became the default place/channel to group, to discuss problems in the system etc then it would almost have to be used whether you want it or not. A better solution to grouping up for a difficult NPC for example would be via a pilot message on the bulletin board, on acceptance you would be able to comm the pilot who posted it no matter what system they were in and you would be able to form a wing, (of sorts). The 'make the galaxy feel alive' argument, (in relation to system wide chat), holds some validity but falls down for me as soon as it turns into 'HODOR', 'Chuck Norris x, y, z', 'shut up noob' and the like, which, sadly, it will inevitably do so. That doesn't 'feel alive' to me, it feels like every other MMO, it feels like I could be stood in Stormwind from WoW, or the Republic Fleet in SWTOR or any other MMO 'hub' you could care to mention. As others have said, you can form your groups/guilds/clans to some degree in the 'groups' section of these forums, you can post your TS details on there, or, if you want them more private, pm them to each user, to a large degree your 'guild chat' is sorted right there, of course some do not want to use voice comms and I'm not sure how to address that tbh.
As for guilds, as others have said, the main 'guilds' in this game are the factions, I realise this is not ideal for some, the counter of 'well I was in the Horde in WoW and still in a guild' is of course valid. But, and this is the big 'but', the one pilot, one ship element in this game is vital to what they are trying to create in terms of atmosphere, in terms of an, (occasional at least), sense of isolation in the vastness of the galaxy, and, I believe, in terms of the importance of feeling alligned with your faction should you choose to back one or the other. I'm not sure a guild 'flying under one banner' within the context of a larger banner, (Empire, Federation, Alliance), really fits, though, I get others do not share that opinion.
I'm sure there will be some more coming in terms of 'grouping' in Elite Dangerous but I doubt very much you are ever going to feel like you are stood in the central square in Stormwind, and I for one, say thank god for that!.