Some areas of service have gone down such as inflight catering, then again others such as IFE have improved over time. Virgin has declined more than most over the years.
Fares have gone down dramatically. I think that I paid c£350 in 1979 to fly London - Toronto. One reason is higher load factors, so if your priority is getting a free seat next to you - tough. Also the premium cabin subsidises the economy, so lets hope that there aren't too many all business airlines set up in the future.
Also remember there are other airlines apart from Virgin available. Most American carriers offer the same standard of service as VS, which leaves BA. If you are travelling eastbound you have a much better choice of quality airlines. Its not perfect but have a look at Skytrax.