Having looked over these books as well as the Five Nations, Dragonmark, and Magic of Eberron supplemental books as well as the Fantasy, Magic, and Powers reference books a number of things came to my immediate attention:
MagicThe Magic system doesn't work well with a straight up conversion from D&D3.5e to GURPS. As a matter of fact, D&D3.5e in general is something people have been trying to convert to GURPS for as long as I can remember. It isn't even remotely easy, though and something the likes of Bruce Grubb has touched on in his own contribution to the community, found here. A large number of other individuals have their own view of how to convert the system, each with their own strengths and quirks.
Add in the fact that Magic is extremely vast and sometimes confusing, it also has some cost penalties that seem to border on the excessive. This has been touched on a number of forums, one of which I have found particularly enlightening at beccaelizabeth's liverjournal post on Resurrection and how it can arguably make sense and how it can be excessive (as it should be).
Since Eberron is all about action and intrigue, it also plays up on the fact that the power level of the heroes are in fact higher than everyone else in the world. They fight against the economy, social structure, and enemies who are not afraid to take advantage of the flaws of their characters despite them having abilities that border on the miraculous. Although the magic in GURPS can fit into that, I'll will definitely need to come up with a way to allow reward for good role play that can tie right into the spellcasting of each player. In a future post I'll detail on how I'll be using a Static Energy reserve and custom spell lists to take advantage of a player's Deeds within the world.
Power LevelGiven my limited knowledge as a GM but extensive experience and knowledge as a player, I'll need to find a way to really gauge my players. I don't necessarily want to bog down too many details with 200+ points worth of abilities. Instead I want to allow players to work at the baseline and work up. GURPS suggests a Power Level of around 150-200 points, and I am inclined to agree.
As I look through the source books, I do find that Warforged in particular and the Artificer profession to which they share their legend are at the core very expensive point wise. Jurgen Hubert's wonderful contribution to the community touches on how he has converted Eberron to the community in great detail, and it is pretty clear which races are going to be the most difficult in order to balance/afford with the 150-200 budget.
Part of the fun will be deciding on how I want to adapt to my "low level" expectations, and if anything simply contribute the Warforged as an exotic "profession." Though similar to the Magic reference above, the Artificer will be by far the most difficult to translate, seeing as how they use enchantments that are invested into other players gear/equipment.
It will likely be that profession by itself that will be the core of a lot of my research, and I only hope that my efforts of building a system that converts advantages into spells will help enlighten myself on to if it is possible, or if I'll need to try some gimmick to get the result I want while using the existing mechanics in a way that hasn't been used before.
The SettingEberron is extremely vast, which means if I want to appeal to the style I want I will need to select an appropriate narrow collection of Racial Templates, Professional Templates, and establish a working economy/status structure. Thankfully a lot of the work has already been put together for me with Incanus' wonderful "Color of Money" post, and I'll need to take the parts I like and run with it.
This is especially important, given that both Fairhaven and the Dragonmark Houses are entirely engrossed with using their power for financial and political power. As such, "Classes" are not as important as the player's place in society, their fiancial influence, as well as their ability to aid the Queen and their respective Dragonmark Associations.