ASP.NET MVC - NHibernate (UoW) + Command pattern?

I'm building a ASP.NET MVC app and would like some feedback for my way to query/execute statements to the ORM.

I'm using Fluent NHibernate, and have mixed the UoW provided by NHibernate with a Command pattern.

My code:

// ICommand.cs (Core layer)

using NHibernate;

namespace MyDemon.Core.Commands
{
    public interface ICommand<out TResult>
    {
        TResult Execute(ISession session);
    }
}

// ISessionExtensions.cs (Core layer)

using NHibernate;

namespace MyDemon.Core.Commands
{
    public static class ISessionExtensions
    {
        public static TResult Execute<TResult>(this ISession session, ICommand<TResult> unitOfWork)
        {
            return unitOfWork.Execute(session);
        }
    }
}

// GetUserById.cs (Core layer)

using NHibernate;

namespace MyDemon.Core.Commands.User
{
    using Entities;

    public class GetUserById : ICommand<User>
    {
        public int UserId { get; set; }

        public GetUserById(int userId)
        {
            UserId = userId;
        }

        #region Implementation of IUnitOfWork<out User>

        public User Execute(ISession session)
        {
            return session.Get<User>(UserId);
        }

        #endregion
    }
}

// AccountController.cs (Web layer)

[AjaxOnly]
[Authorize]
public ActionResult Details(int id)
{
    User userToGet = _session.Execute(new GetUserById(id));

    if (userToGet == null)
    {
        return PartialView("Partials/UserNotFound");
    }

    DetailsUserViewModel userToViewModel = Mapper.Map<User, DetailsUserViewModel>(userToGet);

    return PartialView("Partials/Details", userToViewModel);
}

What do you think? A clever design, or just another "too-much code" approach?