With Cesc Fabregas gone, Arsene Wenger will have to make time between looking for a replacement and trying to sort out Samir Nasri's possible transfer situation to pick the Spanish midfielder's successor as Arsenal captain. The 2011-12 season Wikipedia page has already been changed to state that Robin van Persie will take up the armband, but perhaps Wenger should take a bit more time to consider his options.
Wenger's last four captains have had their spells with the armband end in a sour fashion: since Tony Adams retired on top as skipper of the 2001-2 Double-winning side, Patrick Vieira, Thierry Henry, William Gallas, and Fabregas have lost the armband due to long-anticipated transfers or personal spats, a record which surely has not helped the Gunners in recent years.*
Vieira's captaincy was certainly the best of the four. Two FA Cups and an unbeaten league title in three seasons, due both to the quality and experience of the entire squad as well as the drive and ability of the French midfielder. When he departed for Juventus in the summer of 2005, Thierry Henry was probably a logical and sensible choice to take over the mantle of Arsenal skipper. In two seasons under Henry, the Gunners slipped backward in the league, but made a couple of good cup runs. Unfortunately, persistent injury problems meant that Gilberto Silva wore the armband for much of the end of the 2006-7 season, before Henry was sold to Barcelona.
Gilberto and Kolo Toure were both vice-captains in 2006-7, but Wenger decided to pass over those two and hand the armband to the mercurial William Gallas in the summer of 2007. Despite his temperament, the decision looked a masterstroke as Gallas raised his performances in the first half of the 2007-8 season, including vital goals against Manchester United, Wigan, and Chelsea. However, his leadership crumbled as Arsenal did in the second half of the season, epitomized by his oft-referenced tears on the pitch at St. Andrew's after the 2-2 draw against Birmingham in which...you know what happened.
Gallas continued as captain into the 2008-9 season, finally being stripped of the armband in unceremonious fashion after some less-than-complimentary comments about other Arsenal players. Wenger, in an atypically bold move, passed over Touré again and gave the captaincy to Fabregas, making him the youngest Arsenal captain since Tony Adams. Fabregas' performances with the armband were quite good on the whole, but he was not able to re-form the psychology of the team to prevent two more late-season collapses, and occasionally allowed his personal desires (not in the Ryan Giggs way) to get in the way of the team, namely by playing while clearly injured against Barcelona in the Champions League in both 2009-10 and 2010-11.
And now Fabregas, too, has been sold, and yet again Wenger has to find a new man to wear the armband. Van Persie is probably the obvious choice, but he's not the only option available. The importance of the captain is difficult to quantify, but for a mentally fragile team like Arsenal, a good captain could be the difference between winning trophies and another late season collapse.
The Odds-On Favorite
This is clearly van Persie. He's worn the armband before in the absence of Fabregas, is probably now the best player on the team, has some tenacity and fight about him, and has been with the club long enough to understand Arsenal. On the other hand, he is an injury waiting to happen, and as we saw with Fabregas, a captain can't make much of a difference if he's on the sidelines for half of the season.
The Reliable Guy
Thomas Vermaelen is only entering his third season with Arsenal (and only his second as an active player), but has the experience of captaining Ajax and the Belgian national team, as well as a fiery and competitive streak. However, he has only played one full season for the Gunners, and appointing him skipper could ruffle the feathers of a few more experienced and longer-tenured players.
The Massive Gamble
If Wenger thinks making Fabregas the captain worked, then he may try a similar trick with another very young midfielder. That's right, I'm suggesting that Jack Wilshere could (and probably should) be on the shortlist for the captaincy. In terms of mentality and knowledge of the club, Wilshere is a perfect choice. He's not totally on the straight-and-narrow off the pitch, but neither was Adams, and he was extremely successful as skipper. The problem with Wilshere is that he just doesn't have enough experience yet. While Fabregas had played four full seasons before taking up the armband, Wilshere has had just one, and is a couple years younger than the man he may replace.
Looking through the Arsenal squad, I don't see any other reasonable options to take over the captaincy, which speaks volumes about the lack of leadership in the team. Whomever Wenger chooses, he will have a monumental task ahead in trying to turn around the team and win the fans back.
*For comparison, Man United have had two captains since 1997 (Vidic, this season, will be the third) and Chelsea have had two since 2000.