We hear every year, when a new MMO is coming out, "oh this is the WoW killer, this is the DDO killer." When it all comes down to it, it never happens. The only "killer" was WoW. It totally devasted the EQ population. EQ is down to around maybe 250k subscribers, Compared to the 8mil subscribers WoW has.
No, Vanguard isn't a DDO killer. Granted, what is? DDO doesn't have a high population as is.
Vanguard has potential, but was extremely buggy, even in Beta. The system specs on it or like "OMG". Not to mention the grind makes EQ look fast.
Yes, I Beta tested Vanguard, and paid for 1 month of a subscription. I cancelled after that.