Is the Assassin going to become a rogue paragon path? has anyone heard anything
4e moves away from SAve or Die so I think the Shadow ASsassin Paragon Path with ritual casting and a warlock or wizard multiclass (and/or half-elf dilettante power) is as close as you are going to get.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.