I think Saints sending Bournemouth down would certainly stoke up a rivalry if one is debated as existing at the moment! I cannot see anything other than a Saints win, especially if the match tonight is a draw and Bournemouth have something to play for.
Putting that aside, I think what Eddie Howe achieved at Bournemouth was been incredible, especially if you think of the direction the club was travelling in prior to his appointment. More than any other PL in recent history, Bournemouth's ascent is a football fairytale, a team who rarely got beyond the third tier for most of their existence and who narrowly escaped both relegation from the Football League and financial ruin eventually promoted to play with the big boys. I think they have done extremely well to stay in the top flight for so long and perhaps have been undone by injuries this season and a recruitment policy which has largely underwhelmed. Should they stay up, Howe will sort out the muddle for next season but I think they are doomed this time around.