Yes, the 57 is also a "normal" audio mixer and will play whatever you plug into it, just select the A1-A4 inputs on the PGM knobs. Of course, you won't be able to use the the 57's buttons/knobs/joysticks to control things in Traktor though. And you won't be able to use the 57 as the soundcard for Traktor, but if you're buying the full Traktor Scratch Pro package you get NI's Audio 8 soundcard (which you'll plug the outputs of the Audio 8 into the 57's inputs).

I see. Yeah, I will buy the TSP package which includes the audio 8. Thank you for your feedback tho. I really appreciate it.

Oh one more question. Is it possible to use one computer with serato and traktor installed in it. I'm talking about all my songs (mp3 files) in my computer. Will it messed up my cue points and loop in every songs that I have saved in serato???

it is possible to have both
the cues won't mess up but scratch live cuepoint are not visible for traktor and vice versa.
best practice to use the same library is to use itunes, since both traktor and scratchlive can read that.

coming from having tested various dj softwares, i say you should try and stick with one rather than try and master them all. it is quite time taking when trying to get used to just one software so people get slowed down and most of the time skip on things that could better their performance when mixing.
it is better to know one software 90 percent than two softwares only 50 or 60 each, especially since you'll be using only one per gig

I do not agree, I prefer the Serato philosophy but also prefer the tempo management in Traktor. I got the 57 and TSP, I consider I pay enough to use my harware as I would like. Kontrol X1, S4, Maschine kontrol pads .. are OK with Serato. Serato should be Ok to open the USB protocol and give a true midi signal so as we can use it with any other soft ...
If they don't do it officially, one day somebody will manage to translate the data from a soft to another ...

BAB's

I Agree with BAB's,i have a 57 and Traktor as well,and i use both,i would love to find a way to use my 57 as a controller for traktor.