It looks like these InfiniVision scopes have been around for a few years. Heard anything about possible upgrade in the near future?
unlikely, if anything we might see some slight refresh without any major changes (i.e. sample memory will remain the same).
DSOX2k, DSOX3k and DSOX4k (and their MSO variants) still sell very well. The DSOX6004 doesn't, though (but that shouldn't really surprise anyone considering in what scope class Keysight tries to compete with essentially a blown-up entry-level scope). Many corporate customers tend to buy single-source, so they get all test gear from Keysight (and no other manufacturer has a similarly wide ranged portfolio), and that includes scopes even though they might not offer the best bang for the buck. Also, corporate customers pay nowhere near RRP for their kit.
Also, don't forget that the DSOX3000T only came out in 2014, where it replaced the DSOX3000A. Giving the DSOX2kA the same update would very likely make it too expensive, and the DSOX4kA already has what the DSOX3kT got (the DSOX3kT is pretty much a DSOX4kA with smaller screen). There isn't a lot room for further updates.
It's true that from a technical point of view they are getting a bit long in the tooth (the tiny sample memory is a problem), and the excessive high waveform rates haven't shown to be such a massive advantage as Agilent/Keysight claimed in their marketing blah. But the limitations are mostly due to Keysight's architecture and with that there's always a trade-off between memory size and update rate, which they already decreased from 8M to 4M when moving from the DSO6k/7k to the DSOX to get these superhigh update rates. That means all they could do is going back to where the old DSO6k/7k scopes were. Not a lot to justify investing in setting up a new product.
And as long as the InfiniVision scopes sell well there's no need for Keysight to invest in a successor. And as someone else said, even if they had plans then they're not going to make them public before launch date to protect their existing sales.
As someone already said, there are lots of scopes out there. If the DSOX isn't what you want then buy something else. And if you insist on Keysight then you'll probbaly have to live with what they're offering. That's how it works.
BTW: the DSOX (which I think came out in 2011) isn't really *that* old. Just look at Tek, who sells pretty much the same outdated scope design in slight variations for more than a decade.