It will always feel, look, and sound ridiculous to outfit the 3DS with the Circle Pad Pro, even for games like Resident Evil: Revelations, where it legitimately enhances the experience.
Since the 3DS XL will not include a second stick, Andriasang (via Famitsu) reports Nintendo will also issue another stick add-on.
There’s no word on when it will arrive, how much it will cost, and whether it’ll remain in Japan (doubtful), but if you’re worried about upgrading and having that second stick, it’s no longer an issue.
I still do not expect Nintendo to support the Circle Pad Pro outside of how it was handled within Kid Icarus: Uprising, which made the game far easier for left-handed players.