But perhaps the most intriguing battle is for fourth place and a spot in the RaboDirect PRO12 play-offs.
While the order has not yet been determined, Glasgow Warriors, Leinster and Ulster will occupy the top three positions but Scarlets and defending champions Ospreys are still locked in a tussle for fourth.
Much like last year the Ospreys have embarked on a late run towards the play-offs but while they were unrelenting last season and marched all the way to the final to beat European champions Leinster, defeat to Glasgow last time out took things out of their hands.
The Scarlets know that victory over Treviso on Friday will rubber-stamp their place in the last four but with the wounds of agonisingly finishing fifth last season, that is by far a foregone conclusion.
And while they will have their Lions - George North and Jonathan Davies - strutting their stuff at the Parc Y Scarlets, forwards coach Danny Wilson is taking nothing for granted.
"There is plenty in this game for all our players, there will be a lot of emotion, ambition and expectation flying around so a highly charged game for everyone involved," he said.
"But there's no danger of us losing our focus. The players benefitted from a light week coming out of the Blues game with a break from matches last weekend and that allowed some recovery of battered and bruised bodies after the Welsh derby and to get our minds fit and fresh for this fixture.
"That's meant we've been able to hit training well this week - there's huge desire and ambition in this team to see all the hard work put in all season long really pay off, and importantly to reward our loyal supporters with a play-off place in the league.
"This is effectively a Scarlets quarter-final and as players and coaches we're looking forward to another night of vocal support from our home crowd."
The Ospreys, who travel to Dublin to face a Leinster side looking to secure a home semi-final - and possibly top spot if Ulster slip up at home to Cardiff Blues - have also called on the cavalry.
Head coach Steve Tandy has included four of their British & Lions in the squad - captain Alun Wyn Jones, Adam Jones and Justin Tipuric in the pack, while second-row Ian Evans is named on the bench - and he's desperate to ensure his side's hard work for the season does not come undone.
"I was extremely disappointed with our performance up in Glasgow last time out. We didn't do ourselves justice and that defeat has opened the door for the Scarlets, allowing them to jump ahead of us with one game to go.
"We know that we're up against it if we are going to reach the play-offs but we definitely won't be throwing the towel in."
Denied the chance to claim a third straight European title, Leinster can still complete a double with the RaboDirect PRO12 crown and the Amlin Challenge Cup and will be determined to give outgoing coach Joe Schmidt the perfect send-off.
Schmidt said: "I've benefitted massively from having a superb management staff and a super playing staff at Leinster who have been incredibly motivated."
Waiting in the wings are Glasgow Warriors who are currently third but can become the first ever Scottish side to claim a home semi-final with victory, coupled with either Ulster or Leinster slipping up.
They travel to Connacht who wave goodbye to flanker Johnny O'Connor and head coach Eric Elwood, who passes the reins to Pat Lam next season.
Elsewhere, Edinburgh host Newport Gwent Dragons, who could leapfrog their Scottish rivals into tenth place with a thumping win while Zebre welcome Munster in what will be their last chance for a first ever RaboDirect PRO12 win, having picked up eight losing bonus points.
Forwards coach Vincenzo Troiani said: "This is the last official game of a bad season if you only look at our results.
"The coaching staff and I are satisfied by many aspects of this first season: the growth of the squad both in general and in the individual level and the increased quality of our play that has allowed us to be competitive at least in the last months."
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