Sprint improves its unlimited data plan to play with the big boys

Earlier this week, Verizon announced an all-new unlimited data plan that included HD video streaming and mobile tethering. Not to be outdone, T-Mobile followed suite and added those features to its flagship unlimited plan. Today, Sprint announced that it's adding HD video streaming and mobile hotspot to its unlimited data plan, which I am sure is a total coincidence and in no way an attempt to keep up with the competition.The press release doesn't make clear if this is a long-term change to Spri