Quite a few good things have come from it - making private channels for events proved handy, and similarly for small groups not made up entirely of party or guild members a private channel is handy.
Mostly the 'global' chat has been entertaining, and useful - but occasionally, has been global spamming of insults, highly offensive comments, and attempted gold-seller spam. Without someone watching chat who has the power to kick people off it, or temp ban for breaking the RoC, that's going to remain a problem. Sitting watching outright racist or homophobic abuse for half an hour is NOT an acceptable option, and dropping out of the entire system is the only action left. I can try report the author (but how is not clear to new players), and there's sure as hell no way to get action taken quickly enough... and meanwhile this stuff is appearing on computer screens around the world - not exactly the sort of 'presence' EA want to be associated with, I suspect. I'd also be reluctant to rejoin the system if I was just going to get another screenful of the same stuff, so a global " character '****' has been banned from the chat system" message might be useful.
I see no chance of EA/Mythic being prepared to invest money in paying people to monitor the system properly - on past form, they'll likely chuck that role onto existing staff. They don't seem able to handle the basic run of in-game issues, never mind loading more work onto them, so that seems unlikely to work well. We might get a half-baked 'reporting system' to flag issues, but without anyone immediately active on the other end of such a system, it's a token gesture of no real worth.
Overall, it's been mostly positive - but if there's no proper grip on running it, there's a real mess just waiting to happen.