Nvidia hasn't exactly set the world on fire with its Tegra line of Arm-based mobile processors. Outside of its own excellent SHIELD hardware (and notably the Nintendo Switch), it's basically dead. But the company is hoping to breathe new life into its Arm ambitions by doubling down on what it does best: graphics. In a press release, Nvidia announced that it's working with major chip supplier MediaTek to combine Arm-based architecture with its RTX line of graphics cards.
What does that mean? In the case of this specific partnership, it means suppliers might start equipping Arm-based Chromebooks and other Chrome OS hardware with "RTX graphics." That probably won't be the same as, say, an Intel-based Windows gaming laptop with a discrete Nvidia GPU, but it would be a significant boost over the kind of inexpensive Chromebooks typically equipped built on MediaTek's chips.
Nvidia mentioned support for "ray-traced graphics and cutting-edge AI on a new class of laptops." But the focus for this development seems to be on the performance-to-watt ratio: boosting graphical power without significantly affecting battery life. A natural result of that might be wider support for 4K or high-refresh screens, rather than a sudden boom in console-style games available for Chrome OS. Based on the join press release, highlighting partnerships for consumer, cloud, and scientific/industrial Arm-RTX hardware, it doesn't seem like Nvidia is eager to re-enter the phone chip market anytime soon.
Nvidia and MediaTek are making a reference platform that combines the latter's system-on-a-chip designs with the former's GPU technology, formally announced during the Nvidia GPU Technology Conference (GTC). That means that it'll take at least a year (at best) for system makers like Lenovo or Acer to develop and release MediaTek-powered laptops featuring RTX graphics.
Assuming, of course, that any are interested in actually making them. But I'd take a second- or third-gen Lenovo Duet, with enough graphical power to actually run Hearthstone smoothly, in a heartbeat.