AT&T's unlimited  phone  lineup just got a major shake-up. The carrier replaced its existing plans with  2.0 versions  that generally pack in more features for less money, a noticeable improvement once you factor in the recent price hike on the old, now-retired plans. But the  150-year-old company  didn't stop there: it also rolled out a splashy new flagship  tier  aimed squarely at customers willing to pay a premium. If you're an AT&T customer suddenly bombarded by notifications about upgrading, or you're looking to switch from another carrier , here's a breakdown of the new offerings. These plans replace the AT&T Value Plus VL, Unlimited Extra EL and Unlimited Premium PL plans. The carrier also removed its Unlimited Starter SL plan, which served as the entry-level plan (you had to know where to look to find the limited, but cheaper, Value Plus VL plan). Keep in mind that AT&T plans let each person on an account have their own plan.…