I agree with Andrew that Blood Money feels different from past Hitman games, and not always for the better, but I don't agree that it relies less on stealth. Depending on one's perspective, stealth is more important in Blood Money than ever before.
Andrew mentions many details that, for him, added up to Blood Money being more forgiving than previous installments. I found the opposite to be true. Andrew curiously didn't mention that running-and-gunning is virtually impossible in Blood Money. In past games players could almost always shoot their way out of a level on any but the highest difficulty. The 47 in Blood Money is made of tissue paper compared to the guy who could take 40 bullets to the chest in Silent Assassin and Contracts. Andrew is correct that Blood Money offers the player more latitude in exploration, with more shades of gray between suspicion and full-blown alert, but that's only because a full alert status, for the first time in the series, results in almost certain failure. The combat artificial intelligence (AI) may be dumb as nails, but it hardly matters when one's avatar is so tragically mortal.
Most of the design shifts that Andrew mentioned I'd trace back to one thing: Blood Money's reliance of civilian-oriented levels. Virtually every level in Blood Money takes place in a public space full of innocent bystanders. The previous games had a few such levels, but they also had their share of military compounds and other isolated settings. There seems to have been a deliberate design shift in Blood Money towards pulling jobs in witness-saturated environments, no doubt to take advantage of the new AI system which now logs evidence and notoriety. The system is successful in bringing more complexity to traditional Hitman gameplay. It's very cool to accidentally get caught on videotape during an otherwise perfectly executed hit, and then realize I'll have to formulate a plan for how to find and steal the surveillance footage before I escape… that is, if I don't want people recognizing me in the next level. Situations like this can escalate into darkly hilarious episodes of damage control, as you begin killing witnesses and removing evidence in an effort to protect your anonymity. Consequently, the missions in Blood Money seem much more like what they are: murder.
For all its humor and subtlety, it's debatable whether Blood Money's various design changes result in a better experience. In spite of its numerous advances the overall effect is not overwhelmingly different from previous Hitman games. The added AI complexity is nice but one wonders if more mission variety might have offered more bang for the buck. On the other hand, I found the shorter-yet-deeper mission design more balanced. People often complain about the ruthless trial-and-error gameplay of Hitman, but by shrinking the levels while expanding the possibility space the developers have made the concept of playing a level over and over much less absurd. I played though each mission in Blood Money on Professional difficulty (no saving) and had a blast. When I tried to do the same in Silent Assassin I quit out of frustration half way through.
I miss the greater variety of Silent Assassin and Contracts, but the developers seem to have made a conscious decision to trade variety for greater depth in Blood Money. And while I may or may not ultimately prefer past Hitman installments (time will tell) I doubt I'll look back on Blood Money as a disappointment. The gameplay is still absorbing in that special way that only Hitman can provide, and while the abundance of new features creates some rough edges, the overall impression is still classy as hell.