If I could take you back to Casino Royale Bond had only just got his 00 agent status. It had more of a love theme running through it and hence he lost Vesper. If you remember they said they were re-building Bond to the man he became. This wasn't going to be completed in the one movie and thats why Quantum of Solace takes up the story as a sequel and completes the two film connection The film is centered around the action. In fact Bond does drink a Martini which he had given the name Vesper in the last film. The reason for the ending is to leave it with unanswered questions as to who is behind it and in charge of Quantum, however I think Bond had to go through the process of love and grief. We couldn't have Bond going about his business as if nothing had happened in the last film. Ok gadgets aren't there ect... but really there is enough action with the car chase/ boat chase/ roof chase ect... there was little room for such gadgets and as for the Bond girls one says there wasn't room for a love scene with her and Craig unlike Agent Fields who ends up in a typical Bond girl death. In this one there was more bits of the Bond theme not the full theme but bits intermixed with the soundtrack. I think the 3rd outting for Craig will be more different to the previous two with more like the Bond type films we know as they are slowly building it up rather then give us all the Bond mix.
He wears his tux most of the time and even goes back to using the PPK has his handgun of choice. I can't see people back when Dr No sayin No Gadgets ect... what a crap film. I think we have been overloaded with that side and yes the Bourne films did have this type of look but you must remember if Bond wasn't made on the big screen in 1962 then the Bourne films may not have even been made as it has alot of Bond type ideas in it.
Overall, this film has a different look and style to it. The one thing I would have to say is the title theme isn't as good as previous years.
And one bit of advice. Re-watch Casino Royale then go and see it. You will see that the main plot lacks abit but the opened part of Casino is conluded.