Side by side seating

Why have the Russians/Sukhoi chose to adopt side by side seating in the Su-34?

Every attack jet I have ever seen has always featured tandem seating for the pilot and the WSO. The only aircraft that utilise side by side seating are the larger attack aircraft, I think the F111 could be the smallest aircraft with this seating arrangement.

Are Sukhoi setting a new precident for seating arrangement with the Su-34 and can we expect western aviation manufacturers to copy this idea with any future attack aircraft, possibly even a non stealth replacement for current machines?