Oh dear, a student of media asking for thesus help. Tsk tsk! (I am being cheeky cause a decade ago I was that media student! Well lets see. (I want a thank you mention for this!) 
An anaylsis of Vesper Lynd - By Thunderbird 2.
...The writing of Vesper Lynd, coupled with Eva Green's potrayal of the character truely brings the concept of the Bond leading lady into the 21st Century. Vesper is neither the bra burning feminist woman villan seen in the earlier films, nor the emasculating ice queen boss that M was when introduced in Goldeneye, a character who was seen in that film as a real threat as Bond's superior, something the dialogue made clear from the off. (That relationship has been developed well in part no doublt to Dame Judi Dench's excellent chemistry with Pierce Brosnan and now Daniel Craig.)
The character of Vesper breaks convention by coming from outside Bonds world of espionage. A treasury offical, she is not someone who has lived in a world of death and destruction, but she is a woman of a modern 21st century world, with mixed shades of gray. - Bond himself underlines this point when he snaps at Vesper how high the stakes are, after she tells him he can't have the remaining treasury money due to his recklessness. - If Le'Chiffre wins, he will continue to fund the killing of countless people. In simple terms that cannot be allowed to happen. - Black and white!
Secondly, Vesper is in many ways Bonds female equal. When they first meet on the train she makes it clear he can try as hard as he likes to impress her, it won't wash, and she sizes up his back story (quite accurately)in two seconds flat. The verbal banter between the two makes it clear she is often a step or two ahead of Bond. - Tragically it becomes clear why at the end of the film. She WAS several steps ahead of him all along. Vesper gives Bond the distrustful edge he needs to become the man we know, as well as the key lead he needs even after she dies. Vesper's betrayal is irroncially essential to Bond seeing the world in the way he has to to survive. Underlined by M. - Now Bond knows he can't trust anyone, he is the 00 agent M knows she can send off to do what needs to be done, without making a hash of it, as demonstrated earlier in the film before he met Vesper. - Leading to what we will see in Quantum of Solace.
The writing of the characters is what makes a story work, but in this case Eva Green's slightly aloof, indifferent and vulnerable potrayal of Vesper is what makes it succeed. The woman Bond falls in love with has to be something exceptional, and Vesper is. In the actress's own words "Vesper is like the Sphynx. Enegmantic, mysterious." - We don't really know whats going on with her, and we see her react in different ways. Enegmatic, ****ed off and terrified. The stairwell fight in the hotel is truely graphic, but those of us who know Bonds world from the books and films are used to this sort of thing. However when Vesper goes into automatic mode after Bond kills the two "investors" we see her start to wake up to the horro of what Bonds life is like. This culminates in the heart reding scene in the shower. - She really hadn't bargined on things getting this out of hand right in front of her. - There is a cold irrony in the fact its Bond that comforts her, and she welcomes that comfort, as she was the man who commited the killings she is accessory to. Again the closing scenes put a fresh perspective on this, - she could see her Algerian boyfriend meeting the same fate reflected in those deaths.
All of this shows a multifacted character, with strengths and weaknesses and perhaps most important of all - her own agenda that is not "tacked on" Its there right from the start if you look for it. Eva Green is exceptionally good at using those expressive eyes of hers. Even when Vesper looks out of it in the shower, her eyes having a sad, knowing inteligence. Something reflected in all her scenes.
Casino Royale proved something very important. The most dangerous women in Bond's world aren't the ones that use guns, are built like tanks or have money. Vesper is a women who is capable of being as intelligent, single minded, calculating, carismatic and unstopably dedicated as 007 himself. Its what makes her so damned compelling! I suspect the ghost of Vesper's legacy will continue, not just in Quantum of Solace, but subsiquent films too.
(I hope this helps Mattdonns!) 
Author's sidenote: - Where are the women like Eva Green in the real "everyday" world?!
This is Thunderbird 2, how can I be of assistance?