Mini systems and ghetto blasters and Walkmans were being churned out in huge numbers 25 - 30 years ago and it never spelt the end of seperates then or since.
If there were no profit in budget seperates then there would be none around now.
Last time I looked there are... Cambridge Audio, Marantz, NAD, Rotel, Rega, Sony (just about) all still producing budget seperates and developing new ones.
Yamaha have even stepped back into the 2 channel seperates game for the first time in ages with their S1000 and S2000 range of CDs and amps.
As for speakers, there are plenty at budget prices and even a few good budget turntables still doing well. (Pro-ject and Rega)
In 5 - 10 years time the seperate amps and speakers will still be around, although I think traditional seperate CD players will have started to become a speciality niche by then. (Certainly in 10 years anyway).