Mark, i started out quite skeptical and have not been a fan of WoTc in recent years, but have to say I don't see them making any major blunders here. They are doing about as good a job as can be done so far. Unti we see the actual game we wont know how good the end product is, but I get a real impression of competence and concern here.
I agree they designers are doing the best they can. I get the same impression of confidence and concern. I wonder if they are getting the full support they need from beyond the design team, particularly regarding the OGL/GSL/Licensing decisions. As someone who has been a D&D guy since 1974, I'd love to see this succeed in ways that we haven't seen in recent years, or ever.
I'm not sure anyone needs to see the actual edition to determine if the end product is good, as far as their individual playstyle might be concerned. That's a marketing game that backfired with the last edition and I doubt folks will fall for it again. The
you don't know from the hype, you don't know from the previews, you don't know from just reading, you don't know from just a few games or short campaign, you don't know unless you play for a year can that was constantly kicked down the road isn't going to work twice. They need to impress the market with concrete facts, not just a few folks saying they had fun but can't give any details. The truth that any good game master can make even the worst rules fun isn't a secret and it's only going to be reinforced if that's all anyone has to go on.
I'm not personally skeptical if they can produce a good game, though I wonder how what they will produce will stack up as a roleplaying game. I think they've been making good boardgames. I like the minis games they've made over the time WotC has held stewardship of the brand. The production quality of all of their products is some of the best in the industry. But they've been 50/50 on a viable RPG, in my own opinion, and I know they can do better.
As far as the mistakes being made, I'm using their yardstick of their wanting this to be an edition that can draw players from all editions and playstyles. It's their goal I am using as a standard, not my own. I see the need to get off the fence regarding the OGL/GSL/Licensing as majorly problematic in that, if they moved on this in a more timely manner, they would already have tons of oars in the water pulling in the same direction that are not yet committed to their goal. That's a mistake. Further, the missed opportunity to draw in the support from the players of the earlier editions by not becoming involved in the community via growing conventions like Gary Con is also a mistake. Sure, they might be able to make up for those missteps down the line but they'd clearly be in a better position if they didn't have to make up for them. There's early support they simply are not garnering through their inaction in these areas and I find that disheartening.