Just for reference, I get almost the same score stock(1681) in 3DMk05 with my 128mb ATI x300 in my Inspiron 6000. Overclocked I've gotten 1891 and that's without any tweaking(which I'll be doing soon, trying to get over 2000). Now benchmark scores aren't everything, but ask anyone in the Dell forum that has a x300 and they'll tell you it does pretty decent with games. It's no powerhouse, but it's not meant to be.
If the 7400 is scoring about the same or slightly higher than my x300, then it's not a revolutionary part, sorry to say. It'll definitely be a good budget card, but don't expect anything amazing. I'm still thinking about getting a Vaio FE myself, so I might be able to give an apples to apples comparison of the x300 to the Geforce go 7400. I'll post up if I get a FE.