Rigol would have to revise the DHO1000, equip it with a second ADC, built-in AWG and LA.
However, this would mean that nobody would buy either the DHO1000 or the DHO4000 any more.
Or an upgraded version of the DHO4000, with one ADC per channel in order to maintain the bandwidth/sampling rate for all channels.
But that would be so expensive that hardly anyone would buy it in view of the alternatives from Siglent or even R&S.
As I said, I don't think the current range of models is well thought out.
I would assume that the plan is to keep the current range of DHO models on the market, and complement the DHO1000 and 4000 with sister models, much like the DHO800/900 siblings.
If the follow the DHO800/900 lead, these "big sisters" would be closely based on the DHO1000 and 4000, respectively. They would include the LA and AWG, and some further, minor differentiating features: Maybe "slightly better" bandwidth, if Rigol follow the DHO800/900 pattern; include full memory option of the smaller model as standard; throw in some software/analysis features.
Something like these -- just speculation of course:
DHO2000
- 2 GSa/s (single ADC)
- 150 and 300 MHz bandwidth?
- 100 MPts memory
- Logic Analyser
- AWG (in -S model variant)
- I²S, power analysis?
DHO5000
- 4 GSa/s (single ADC)
- 200, 400, 800 MHz bandwidth
- 500 MPts memory
- Logic Analyser
- AWG (in -S model variant)
- I²S, power analysis, what else?
As a further step, there's room above the 5000 for a dual-ADC model (or even quad) maybe?