They are two completely different events though. And Trials should have already been available as a weekend event anyways. I was more looking forward to doing ToO this weekend than HM.
What that matters? There is a lots of players who do PvE & PvP, and want get on all those events. Stacking events, even if one is for PvE and one for PvP, is stupid as it forces a lots people to choose or schedule hardcore around the fact that there is two time consuming events going on over single weekend.
Yes I know that ToO is weekend only while HM Raid is on 24/7, but I think we are smart enough to acknowledge that more HC players want to be there on day 1. For both events, ToO and HM release, if they were stacked.