Accessing more than one data provider in a data layer

...
IDaoFactory daoFactory = new NHibernateDaoFactory(); //instantiation in main class
...
SamplePresenterClass s = new SamplePresenterClass(daoFactory);
...

List<string> LoadData(LoaderEnum key)

ILoader loader = new XMLLoader();
SamplePresenterClass s = new SamplePresenterClass(daoFactory, xmlLoader);

SamplePresenterClass s = new SamplePresenterClass(daoFactory, xmlLoader, sampleWebServiceConnector1, sampleWebServiceConnector2, ...);

public class DataAccessHolder
{
    private IDaoFactory daoFactory;
    private ILoader loader;
    ...
    public IDaoFactory DaoFactory
    {
        get { return daoFactory; }
        set { daoFactory = value; }
    }
    ...
}

DataAccessHolder dataAccessHolder = new DataAccessHolder();
dataAccessHolder.DaoFactory = new NHibernateDaoFactory();
dataAccessHolder.Loader = new XMLLoader();
...
SamplePresenterClass s = new SamplePresenterClass(dataAccessHolder);

DaoFactory<SamplePresenterClass>.Create(); // or
DaoFactory<SamplePresenterClass>.Create(id); // etc

interface IDao
{
    IDaoProvider GetProvider();
}

interface IDaoProvider
{
    IDao Create(IDao instance);
    void Update(IDao instance);
    void Delete(IDao instance);
}

static class DaoFactory<T> where T : IDao, new()
{
    static T Create()
    {
        T instance = new T();
        IDaoProvider provider = instance.GetProvider();

        return (T)provider.Create(instance);
    }
}

class Cat : IDao
{
    IDaoProvider GetProvider()
    {
        return new XmlLoader(YourEnum.Cat);
    }

    // ...
}