My 50 cents:
I think the reason why F1 2013 has been a disappointment is because their focus was elsewhere. They had to add a whole new aspect to the game, which was the classic cars, and this must have taken them lots of time to make; time that could have been spent elsewhere.
I also think that they had in their mind that their next game (F1 2014) would be on the next-gen consoles, and therefore no need to go all the way with new features in 2013. This is also one of the reasons they got dislinked with their sponsors for their community website (i think it was on purpose. It doesn't take that much time to get a new website up and running for a community site). I hope and think 2014 will be a good year game-wise.
The PC will of course benefit from the next-gen consoles and the F1 2014 game. It's like when PS3 came out, FIFA got a LOT better on the consoles, and also on PC's. The next-gen's will give PC users a lot better games in the future, and it's quite exciting.
Personally I have a few pointers to how the 2014 game can be a lot better:
1: Codemasters need to focus more on 2014 content rather than more classic content. The 2014 content is just much more important, and no leagues are racing in classic. Their counter-argument would be that they would lose a lot of casual players, if no new content is improved or even added, but if the 2014 content is getting better, the online community will be bigger, where as the sprint races will work again (no one is playing online any more, it's really empty on both PS3 and PC's compared to 2012).
2: Career... Where should i start.. This is such a big aspect of the game, which a lot of drivers are playing. If it were a little better, i think all users of F1 2014 would use it. It needs a bit more variety and some more things to do. Some users said they would love to have the possibility to create their own team, or to take over an old/current team, and develop parts and such: this is not possible for Codemasters, as they have a license they must respect. Codemasters are making the official game of Formula 1, and if they allow users to create their own team, it would be against the FIA license which has been given to them. But still, career needs some more improving, since this is key to the game. A big feature.
3: Well the handling in 2013 is actually okay, but we still need better Force Feedback (wheel users). The way the car feels is great, but compared to real Formula 1, it's ridiculous. For example, if you look at how hard a real F1 driver can turn his wheel, you will notice the difference from real world to the game. These kind of things annoy the hardcore fans, and they are easy to fix, and they need to be fixed.
4: AI: .... they are seriously stupid... The big screw-ups they make, are 1st lap retardness and blocking while hotlapping during qualifying.
Anything else about them? Well yes.. take a drive, and you'll see all the errors in just one race. It's like Codemasters don't even try their own game, and if they do, they must ignore the bad factors, and try again next year.
If modders can make the AI better, you can too with patches, Codies!
5: Community: Codemasters needs to listen to their community! The tire wear this year has been fun and real-to-life, but there are one to three tracks which are way off. The tire wear is just not as it's supposed to be on tracks like Nürburgring and Hungary. People has posted this but no answer.
Generally people has come up with a lot of great ideas to patches or upcoming games, and no answer from Codemasters.
Please log on to Blizzards game websites and take a look how often an admin responds to what the users have to say. They do it A LOT!.. No wonder Blizzard is such a huge company.
I have a lot more points and ideas to the F1 2014 game, but i see no reason to post them, as Codemasters won't read it.
To sum up: Yes! PC will benefit from next-gen consoles graphic wise. Handling and in-game features will be the same development.