That system will be fine for ArchiCAD 11, although it won't be a rendering demon, if that's what you're after. Desktops will still beat laptops at that any day of the week.
Also, the Turion doesn't have anything on Intel's Core 2 lineup, so if you want rendering power in a laptop, go for a Core 2 Duo. About 2.4 Ghz is good, or you could wait around for Intel to start shipping Mobile Quads in a few months.
Also, skip Vista and install XP Pro SP3 instead. I've never seen a laptop, no matter how powerful, run Vista with even close to the stability and speed of XP.
And last, the GeForce 7150 will do alright, but it's as close as you can get to the bottom of the heap at the moment. for decent sized models, the 7600 is a much better option which will take pretty much anything you can throw at it.
Sorry, one more thing. You'll want to either get an external monitor, or up the resolution on the screen. 1440x900 is nice for a while, but the very short vertical size is going to get very annoying in ArchiCAD after a while.
Josh Osborne - Central Innovation
HP Zbook Studio G4 - Windows 10 Pro, Intel i7 7820HQ, 32Gb RAM, Quadro M1200