It's always a great shame when a driver is killed on a cirquit, especially the young ones with their whole life in front of them. Also it's very bad when a spectator is killled, becase they just come there to see a race, and hasn't accepted the risk, like the drivers have. Also deaths works only as fuel for thos who want's to kill off motorsports. It's a good thing that F1 is as safe as it is now, who wants to go back to the 60s/70s where every seventh driver was involved in a fatality? And like Jackie Stewart said if you were racing competitively for about five years back then there was a 2/3 chance that you would die in a crash, he knows very well as he was almost killed himself in a very bad accident. Stewart was actually one of the first to stand up and try to do something for the drivers safety.
Like KaJuN pointed out there was almost a fatality in Australia this year, and that is the point these guys still put their lives on the line every time they get into that car, motorsports and formula 1 in particular is safe untill the wrong accident happens, the one the engineers never thought about. By the San Maring GP in 1994 there hadn't been a fatality during an F1 race since Gilles Villenueve in 1982 and the general concensus was that the sport was tamed. Right now there has gone a similar amount of time.
On the other hand though, these drivers died doing what they loved, and I'm sure that if they could choose which way to go, this would be it.
Allthough I think they could loosen up the rules a bit and allow turbocharging to come back along with ground effects, not as extreme as Brabhams BT46 "fan car", but they could allow the usual big venturi tunnels. Turbocharging would be nice in the way that using it in formula 1 could over time improve the technology going into normal road cars, unlike now when the use pneumatic valves running on gas to let the engine rev to like 19000 rpm creating such insane amounts of power for it's size.