Vader's 25th Anniversary show in Warsaw on August 30th with death metal all-star line-up:

Samael
Entombed
Nile
Septicflesh
Grave
Dismember
Gorefest
Marduk
Rotting Christ
Vader

That's 10 bands and over 10 hours of death metal (well, occasionally black metal, but that's also cool w/me). I may end up not listening to dm till the end of the year