I was a little surprised by the lukewarm reception to The Lodger. It is so far above any modern-day Ripper film, it definitely deserves a look.
I haven't seen the 1940s film, but I have seen - many times - the Hitchcock 1926 silent film. I felt the echoes of it throughout the remake. As a fan of Hitchcock, I found it pretty cool that the directors didn't muck it up like so many do when they try to contrive Hitchcock-like scenes.
Simon Baker is perfectly cast as The Lodger. He looks a bit younger with dark hair and has this secretive way about him that lends mystery to the character.
Frankly, I didn't pay much attention to the shenanigans of the PD, which seemed to be a turn off for other viewers, according to reviews here. Let's face it: This is a PR nightmare for the department, so someone needs to hang for it - and that just happens to be Alfred Molina's character. It works well into this film and casts a glare of suspicion on officers who may or may not be the killer.
Overall, The Lodger remake keeps you slightly off-balance while trying to guess the whodunit. Most, I think, won't know who it is until the very last frame.