And others have also checked directly with apple and were told it would NOT void the warranty. They simply wouldn't warranty the ram. Just like they won't warranty the ram installed by expercom.I checked directly with Apple a couple of days ago and was told if I install additional RAM in a mac mini myself, the warranty would be voided. I ordered a mini from Expercom this morning and had the option of buying it with Apple RAM or Expercom RAM.
Even if it were an issue you'd simply put the old ram back in and then take it in for warranty work. They would never know.