Looking at all of the conditions of the Brightline takeover of Xpresswest, one of them is acquisition of 38 acres at the Las Vegas "Strip" for a station and multi-use development. Brightline has experience with that - their Miami station is a multi-use development. Otherwise, the list of conditions is long and while I don't think the issues are at all insurmountable there is ample opportunity for the deal to fall apart (again). Still, Xpresswest has the NEPA work done, preliminary engineering done, at least some permits are still valid, most of the right of way is in order, etc. They've been waiting for a Shining Knight with Money to move them on to the next step (briefly, that was to be the Chinese, but that also failed). Read the acquisition details at the XpressWest web site.

The original XpressWest design was for 150 mph using Siemens EMU trainsets. That would have produced a less than 1 1/2 hour schedule from Victorville to Vegas with no stops (Barstow isn't happy about that, and may yet sue if the project comes back to life). The Siemens diesel trainsets that Brightline got for FL use are 125 mph designs. It's not clear yet whether a Brightline version of XpressWest would be electric or not, but if not your points about the feasibility of diesel power above 200 kph/125 mph may come into play, with a longer trip time. At 2 hours, the trip would approximate what people think they can drive it in (at considerably above the speed limit), even though the vast majority of the time the drive takes (much) longer, reducing potential ridership of course. The 150 mph speed target was chosen deliberately in the original design to optimize cost v. trip time; it's also coincidentally the maximum speed currently used in (small parts of) the Amtrak NE Corridor for the (electric, not diesel) Acela high speed trains.