Having had a MacBook Pro since April '06 I have had time to evaluate its features. The Magsafe connector is a great idea but there are a two problems with it. The first is the shape of the plug into the computer.
As this is a portable machine I take it with me and if I think that there is a chance that I will need more than three hours of power, I bring my charger. This means that I wrap the cord around the dogs povided on the adaptdor and stuff it into my bag. Here is where the first problem arises. The edges of the plug which go into the computer are sharp and tend to catch on things like, anything in the bag or the zipper itself. This on a contunuous basis could comprimise the cord to plug connection.
Secondly I noticed than after forming a sharp bend in the cable, it seems to produce a permanent kink in the line which leads me to believe that the wires are placed loosly in the cable sheath. I have seen reports of kinks in the line next to the plug where it goes into the computer. My cable also does this. Upon a scrutinization of the plug end I noticed that the two middle contacts of the four are slightly more recessed into the plug than the outer ones.
This brings to mind the report earlier this year of a plug frying itself. If the contacts are in the precarious situation of ALMOST making contact the resulting arcing could cause them to burn out.
This is my theory.
The MacBook Pro is a super machine and I am very happy with it.
Cheers:
Bob

Hey everyone - we have this great new "magsafe" connector that is designed to be the "weak point" that disconnects before any other parts get damaged due to strain on the cable.

But... if any other parts get damaged due to strain, it's your fault, and not covered under warranty.

Bravo Apple.

I had this problem on my MacBook Pro. This is just one of the MANY MANY problems I've had w/ the machine. It got so bad that I the wires became frayed and would no longer charge my machine. I brought the adapter into the apple store and they ordered a replacement pronto. I also have to agree with the commenter above about the sharp edges being a cause for concern; looks nice, but functionally problematic.

on any cord with a connector at the end one shoulkd never pull on the cord to remove. Always grip the connector to remove. Strain releif is exactlt that - it releives the strain caused by the weight of the cable pulled by gravity. It is not a grip to pull on.
You might notice that old floor lamp cords or other house appliances that get their cords tugged on have the same problem of fraying, which can cause a short. those are purely the users fault and never covered by warranty.

Apple should be a good sport and admit it is a fundamental design fault. Then redesign it and win more loyalty and customers with their 'renowned' customer service by replacing the 'faulty' ones. In my book (no pun intended), it's similar to the Sony battery fiasco and another potential cause for an Apple notebook to go up in flames (an own goal in this case). Cheaper to replace the badly designed cable than to save the corporate image after it happens. How about it Mr. Jobs?

UPDATE:
Apple has now replaced my "swelling" battery on my 17 inch Macbook Pro.

I also went to a different Apple store in my area and talked to a person at the genius bar and simply asked them to replace my fraying adapter because I was afraid it would fail soon.

She replaced it right away. As I walked out she admonished me to make sure I pull it off by the plug and not the wire in the future!

I'm sorry but the current design encourages removal via the wire. It is the fastest way to remove it and I'm sure everyone like me has "demonstrated" how it works by simulating an accidental removal multiple times.

Time for a rev. 2 of adapter I think.