Virgin Mobile has just announced it will launch its first "4G" phone, the HTC Evo V 4G for $299.99 on May 31st. The Evo V 4G will run on Sprint's WiMax network, and Virgin Mobile will offer a $35 plan with unlimited data and messaging plus 300 minutes of talk time. Of course, "unlimited" data is a rarity these days, and Virgin Mobile's plan is no exception — the plan comes with 2.5GB of "full speed" data, so it sounds like bandwidth throttling will take place after the limit is reached.

As for the handset itself, it looks like a rebranded Sprint HTC Evo 3D, with the notable removal of the 3D screen. It has a 4.3-inch, 960 x 540 display, a 5-megapixel, 3D-capable back-facing camera (plus a 1.3MP front-facing camera), 1GB of RAM and 4GB of internal storage, just like the Evo 3D. One big step up for the Evo V 4G is that it'll be running Ice Cream Sandwich, although it'll only have Sense 3.6 onboard rather than the newly redesigned Sense 4 that HTC's putting on the One series. Since it's highly likely this is just a modified Evo 3D, there's also no Beats Audio on board.

Along with its new WiMax handset, Virgin Mobile has also introduced two new Mobile Broadband devices that'll connect to Sprint's WIMax network. The Sierra Wireless Overdrive Pro 3G / 4G hotspot is unsurprisingly a rebrand of Sprint's model; Virgin is offering $35 / month plans for unlimited 4G data plus 2GB of 3G data. If you step up to the $55 plan, you'll get 5GB of 3G data along with the unlimited 4G connectivity. Virgin's also offering the U600 3G / 4G USB stick with the same mobile broadband data plans. While Sprint may be rapidly transitioning away from WiMax in favor of its new LTE network, its old "4G" option will likely stick around for a while thanks to Virgin (as well Boost Mobile, another Sprint MVNO.

Update: We just heard from Sprint that 4G data is truly unlimited and will NOT be throttled — the throttling only applies to the usage of 3G data. This contradicts Virgin Mobile's PR that says the first 2.5GB are "full-speed" without any note mentioning which network you're using. While Virgin Mobile clearly needs to explain this to customers when its 4G products launch at the end of the month, it's good news for those who are well-covered by Sprint's WiMax network.

Update 2: Despite Virgin Mobile's site and PR making absolutely no mention of it, we discovered that the HTC Evo V 4G is identical to the Evo 3D in every way, including the 3D screen. Check out our hands-on for more details on Virgin's new hardware.