The overlay sounds nice but I don't see how it can compete with TS3 for ease of use. And overwolf can fill in where Teamspeak lacks, or so I've heard.
I wish one of their advertising people could see this. This is exactly what a sponsorship is supposed to do.
Yeah, raidcall came out of nowhere and started sponsoring big teams and events. They are probably backed by some bigger company. Its sorta like skype for gaming.