@Nachtfalke:
Since pfsense 2.1 is using .pbis the packages are independent from eacht other. Each package uses its own dependencies and other packages do not influence this package.
But you should check if your packages are testes and do work with pfsense 2.1:
http://forum.pfsense.org/index.php/topic,50603.0.html
That may be the case in the strict sense of the definition of package dependencies, and it's a progress over earlier versions, but there are other things. Like nothing stops you from installing two packages that do the same thing, which is easy to do, because several packages do multiple things, and most are not listed by function but by some fantasy name that the project gave itself, which incidentally is also then a problem in the menus, because related functions are not grouped, which they were if things were named according to the service they provide. Example: "http proxy" instead of SquidGuard, "http server" instead of apache, etc.
The project name could follow the description in parentheses or something like that but the name shouldn't obscure the function.