HTML5 is still a W3C Working Draft standard (see http://dev.w3.org/html5/spec/) and is still changing so browser developers are slow to spend effort implementing it. Even after it becomes an official 1.0 standard, some browsers may not implement parts of it for years, so some amount of browser-specific code (and occasional non-availability of some features on some platforms) will always be a fact of life when building Web UIs.

Just switching from a fragile tile-covered aircraft strapped to the side of a flaking-foam-covered hydrogen tank to an inherently ballistically stable capsule placed as far from the flaming end of the rocket as possible (i.e., on top of it) will achieve the desired 10x safety factor improvement. NASA has been tied to its delta-winged boondoggle for several decades too long. If they would eliminate the segmented, non-throttleable solid rocket boosters (currently still in the plan thanks to Morton Thiokol's lobbyists) they could improve safety another 10x. And if they want to do all this at minimum cost, they could just buy Soyuz vehicles, the world's safest, most reliable manned space transportation system. Of course, national pride would allow this to happen only sometime after Putin declares his undying love for country music and Harley-Davidsons.

HTML5 canvas has a lot of potential. Once accelerated 3D graphics in the browser is standard, the potential uses and demand for content will be huge: visualizations, innovative interfaces, attention-grabbing content, digital art, games...
But IE doesn't support canvas so any site that relies on it for anything more than trivial rendering will be unusable by almost half of Internet users (current IE browser share: ~40%, according to w3schools). Probably Microsoft sees canvas as a threat to Silverlight so won't work with it until they absolutely have to.
Here's a canvas animation demo I wrote. Looks fine on Firefox, Chrome, Safari, iPhone... barely works on IE using emulated support for the canvas element.

Here's my latest HTML5 canvas demo: http://3.paulhamill.com/html_canvas_animation
Should work fine on recent Firefox, Safari, Chrome, iPhone browsers. Animates with glacial slowness and lower quality on IE since this uses excanvas.js emulation. Non-functional on Konqueror.
More canvas demos: http://www.canvasdemos.com

The elephant in the room (which doesn't get enough attention) is that the Ares rocket design is fundamentally flawed due to politics taking precedence over engineering. The Ares first stage will be a solid rocket booster which not only is inherently less controllable than a liquid fueled rocket (since it can't be throttled), but also makes the whole vehicle aerodynamically unstable (since it has a smaller diameter than the upper stage). The proposed reusable solid first stage has the same segmented design that caused the Challenger shuttle explosion when inter-segment seals burned through. It may have problems with severe in-flight vibration which cannot be dealt with by throttling engine power, leading to absurd hacks involving giant shock absorbers. Why is this poor up front design being officially pitched by NASA? Because of the high-powered, big money political lobbying of Morton Thiokol, the Shuttle's Solid Rocket Booster producer, which saw its meal ticket vanishing with the Shuttle retirement. Why has every other human-rated rocket (aside from the Shuttle) been liquid fueled with progressively smaller stages? Because the engineers went with the best design instead of having key pieces decided a priori by senators with law degrees and pockets full of contractor dollars. It will be truly pathetic if NASA winds up with another unreliable, problematic, unsafe vehicle due to back-room lobbying by government contractors. NASA engineers realize the truth which is why they are openly calling for a better design concept. Morton Thiokol should be forced to independently build its own solid-fuel rocket and participate in a fair competition with other rocket designs instead of using back-channel politics to sell its products.

In April 2008 a Soyuz made an uncontrolled reentry due to failure of the service module to separate during the de-orbit sequence. The cosmonauts survived due to the inherent ballistic stability and fail-safety of the design:
http://www.spectrum.ieee.org/may08/6229

NASA has finally conceded that the safest place for the astronauts is on top of the launch stack, with abort rockets to escape a failing lower stage, and with no exposure to damage from falling debris. These factors plus the increased safety of ballistic reentry explain the return to capsules with the Constellation system.

Shuttle vs. Soyuz Reliability
http://forum.nasaspaceflight.com/index.php?topic=7954.0

Soyuz vs Shuttle
http://salul.wordpress.com/2008/09/25/soyuz-vs-shuttle/

The mainstream media once again lives up to its long history of mangling science stories.

The report cites 5 specific fatal aspects of the loss of Columbia: depressurization, extreme dynamic loads, separation of the crew from the vehicle, exposure to space, and ground impact. Implying that this really means inadequate restraint systems is a joke. No amount of safety hardware would permit surviving the breakup and uncontrolled re-entry of (pieces of) your spacecraft.

Due to NASA politics, the report omits a more accurate summary statement that the Shuttle is an inherently flawed and unsafe design when compared to ballistically stable capsules that can and do survive uncontrolled re-entry.

http://3.paulhamill.com