There should be no doubt that Apple's decision to block Flash from iOS in favor of HTML5 has spurred Adobe to make sure that its media-rich content-building tool and player Flash remains competitive. Flash Player 11 brings hardware-accelerated graphics support to the platform.
According to Adobe, the new Stage3D technology in the new Flash Player brings combined 2D and 3D acceleration that is up to 1,000 times faster than the previous Flash iterations. While currently Stage3D is supported only for personal computers, it should make its way to mobile devices in future Flash releases. The advancements offered by Stage3D should bring far more complex graphics development for the player, and allow some developers to use it as a viable alternative for their projects, especially for cross-platform efforts.
Mac users take note: Flash requires OS X 10.6 or later running on an Intel platform since Adobe removed support for PowerPC Macs in Flash 10.
Although it's possible that HTML5 will at some point unseat Flash as the dominant code for media on the Web, that won't happen for a while yet since HTML5 standards haven't even been finalized. The Flash Player is a must if you want to experience the Web at its fullest, so users at any level of expertise should have no qualms about installing or upgrading.