During the DVD-Audio/SACD format war, Pioneer tried to bridge the gap with the first "universal player" that would play both formats. Sadly, it was too little, to late, and both formats are nearly dead.
Over the years, other companies like Denon and OPPO have come out with Universal players for those that still have DVD-A/SACD discs.
These days, Universal players are Blu-ray players that also happen to play DVD-Audio and SACD.
Although there was talk of one, a universal player that played both Blu-ray and HD DVD never came to fruition.
HomeTheaterReview.com's reviews of universal players include:
Oppo BDP-83 Special Edition universal player
Teac Esoteric DV-60 universal player
Denon DVD 2900 universal player