I have to agree about the guy's voice. I know intonation is different in different languages, and I can't fault the accent, but it seems the stress isn't being placed on the right syllables. It sounds a bit like synthetic speech, all the words spoken separately and cut together to form sentences. It ruins the flow, and makes it impossible to concentrate on what he is saying. Also, I think the VA is trying a little too hard to make his voice sound rich and plummy. That might be fine for a dramatic speech, to a crowd, but when speaking to his family, it makes him sound awkward, and it reduces the feeling of a connection between them, rather than the tender moment it could have been.
And, I've always disliked the over-american children in the vanilla game. How do they grow up with an accent like that, and then suddenly turn totally different? In previous TES games, Nords sounded american as advlts too, so it wasn't an issue...
For that matter, there's a lot of VA choices in Skyrim that I think are regrettable. What's up with the pseudo-Cockney Dunmer? You could respect them in Morrowind. And the inexplicably Irish Imperial in the opening scenes of the game?
If I said your voice actors did as well as those in the original game, it wouldn't be the compliment it might seem, but it's certainly not bad. If they work on making the emotions and relationships seem genuine, and maybe a little broader emotional depth for the main guy (less monotone, more flow, and dramatic pauses where appropriate), it'll be excellent. The kid is less of an issue, as it's in the original game (perhaps puberty is more dramatic in Tamriel?), although it'd be a nice opportunity to improve where the original fell down. Great potential in the VA, but for me, that take wouldn't make the final cut.
I like the look of the mod, and I think it's very ambitious, but I don't doubt it'll be finished, and be one of the best large mods to be finished for Skyrim. I'm picky, is all

[I'm English, and quite well-spoken, to give context to the previous. That doesn't mean I think people should sound like me (of course not!) but I know how the english language flows.]
edit: Actually, the man's speech after the kid speaks up is a lot better. It has more of an emotional feel, I like it. Treat my criticism as advice, based on my opinion, it's not intended to be derisory, but helping to make this achieve the mod's full potential. If you sound like a robot, people switch off.