Like Martial Power before it, Arcane Power provides a number of additional multiclass feats for the arcane classes. Some of these have prerequisites requiring you to already have a multiclass feat before picking them up, but other ones can be the first multiclass feat you take. Bardic Ritualist is one of these. The only prerequisite for taking it is that the character have an Int 13 and Cha 13. For a heroic tier feat, it certainly gives a lot.
To illustrate this, I am going to use my eladrin warlord Almirith as an example. When Almirith reaches 4th level, I have been considering giving him the Ritual Caster feat. This would allow me to play up the magical nature of the fey without going the multiclass or hybrid route. Of course if I went the ritual caster route, I might have to consider taking Skill Training: Arcana down the road, just to make sure I could hit some of those ritual DCs.
On the other hand, I suppose I could just take Bardic Ritualist and get it over with in one shot! Not only will Bardic Ritualist grant the Arcana skill, duplicating the Skill Training feat, but it grants the Bardic Training class feature as well. Bardic Training grants the Ritual Training feat, a ritual book with two free rituals, and the ability to perform one bard ritual per day per tier without expending any components.
On top of that, since it is a multiclass feat, you are considered a bard for purposes of qualifying for feats, paragon paths, and epic destinies. This may not seem like much, but in Almirith’s case it will open up the Feyliege epic destiny.
Now, I am not trying to say that any of this breaks the game. After all, not everyone wants the Arcana skill or the ability to cast rituals. So unlike Weapon Expertise or Implement Expertise, this is not the case of a feat that is “too good to pass up”. However, it does make me wonder why anyone who qualifies for this feat would ever pick up Skill Training: Arcana or Ritual Caster!