Update: Following the announcement that HD video would come to its ONE Unlimited plan at no additional cost, T-Mobile has now revealed that the feature also won’t need to be activated on a daily basis.

Previously, the HD video option was available to subscribers of its $80 and $95 plans as an “HD Day Pass” — a feature which, as the name suggests, would only last 24 hours. Thankfully, starting Friday, HD video will only have to be enabled once on its $70, $80 and $95 plans and will stay that way as long as the customer remains a subscriber.

Verizon’s surprise move to offer an unlimited data plan for smartphones and tablets once again, several years after it stopped offering those plans to customers, is already causing one of its competitors to make some changes. John Legere, the outspoken CEO of T-Mobile, revealed the company’s plans to tweak its ONE unlimited service, starting on Friday, February 17.

Legere used his Twitter account to reveal those changes. The big ones will allow current and new ONE unlimited subscribers a way to access HD streaming video, along with 10GB of high-speed data for mobile hotspots, at no extra cost. Those changes match what Verizon currently offers in its unlimited plan. It’s also an improvement over T-Mobile’s previous limit of 480p for streaming video and just 3G speeds for mobile hotspots for its normal ONE plan; you could get HD video and high-speed mobile hotspot data by spending $15 a month more for its ONE Plus plan.

Legere also stated that the company will launch a promotion that will price two lines of T-Mobile’s ONE unlimited plan for $100 a month. It’s not yet clear how long this promotion will last. Normally the price for two lines would be $120 a month.

T-Mobile’s changes to its ONE plan will likely be followed by Sprint and, we hope, AT&T sooner rather than later. Sprint still limits video streaming on its unlimited plan to 480p. More importantly, AT&T’s unlimited plan is limited (no pun intended) just to customers who also sign up for the company’s DirecTV satellite TV service or its U-verse fiber internet provider. AT&T is starting to look like a dinosaur compared to its competition, so hopefully we will see the carrier take some action to take with the other big wireless providers ASAP.

What do you think of T-Mobile’s tweaks to its ONE unlimited plan? Let us know your thoughts in the comments!