I find the addition of both the 800 and 900 series models to be an 'interesting' decision.
It feels to me as if the mixed signal capability was wished for by the product manager for the DHO1000 and DHO4000 series but wasn't possible to deliver within the timescale slated for their release, hence it was pushed down in the backlog, to be implemented as a feature for the later 900 series. Amongst other things, the cost of additional LA probes becomes less disproportionate set in the context of the price points of these models. The 10" displays on the DHO1000/4000 also seem more suited to this, rather than the much smaller 7", lower resolution displays used in these 'portable' form factor units. At least, if you're someone whose workflow doesn't generally have other PC-based instruments up and running in parallel.
Speaking for myself, I'd much rather have seen the LA capability in the DHO1000 and had no DHO900 series. The DHO800 series could have had more memory (at the same entry price), and the sig gen as an option.
However, as another member has previously said, I look forward to being able to complement my MSO5000 "daily digital driver hot hatch" with a more sedate yet elegant drive for the weekend in analogue country. The entry price for the DHO800 is very interesting, and entirely in a welcome way.