At least under the last CBA these "rentals" were mostly veterans who were somewhat past their prime -- like Ray Bourque, for example. These were players who were 31 or older who would be unrestricted free agents at the end of a season, and they were traded because their team did not plan to re-sign them.
Look how awful the NFL system has become . . . contracts in the NFL don't mean anything because players can be cut at any time (imagine Michael Vick getting cut 90 days after signing a 10-year contract with the Falcons!), so you have all these "unrestricted free agents" out there who are no more than 24 years old and just entering the prime years of their careers.
Bourque wasn't a rental, because they kept him for the next season, and would have kept him after that if he hadn't retired. The true rentals the team that gets them at the deadline make no attempt to resign them, they're there for one Cup run and how ever that turns out they won't be wearing that jersey next year.
I don't see anything awful with the NFL system except for the true career players. Players could be cut at any time LONG before the salary cap went in place. The real source of the bogus long term contract in the NFL isn't the cap but what I call the "respect clause". Some players feel they're not getting respected unless there's a huge bottom line to the contract, so teams give them these huge backloaded contracts that they have no intention of honoring after 3 years, but at least the player is getting "respect" so his agent can't put a bug in his ear, and they'll renogiate things later.
Only 24 year-old unrestricted free agents I see are the under peformers like Cryin Ryan.
This may be true, but I can't think of any other sport that generates the NHL's kind of excitement over deadline day. I know I'd always br tuned to ESPN or sports radio just to find out who thinks they can make a run at the Cup and who was giving up. Watching to see who made what moves and what did their rivals do in response. Who went after the big names and who just wanted to sure up a young blue line with a "cagey" vet or who went for a "mucker" for the corner game or a brute to stand in the crease. Sniff.....sniff... I miss it now.