I have a Sony HDR-HC1E HDV 1080i . Around 50 DV tape i will "export to tape" ta an externial harddrive for backup.
I have uset Adobe Premier with cineform and Edius. But in future can be another program. So what format shall i go for when have this as a backup like my DV tapes?
Is m2t safe? Can i then use cineform to convert from m2t to avi?

What apps shall i use? DVD splitt or Adobe premiere CS3 or?

If you want to back up your raw tapes - i.e. the original footage - then capture them via firewire to your hard drive. This will produce lossless, bit-for-bit copies of your tapes in mpeg2 transport stream format (i.e. m2t).

"Export to tape" is usually used in the context of exporting edited footage. If you export edited material to .m2t the edited portions of the tape will get recompressed ... this will not be lossless. In this situation you are better editing and exporting in Cineform avi format.

I want to capture my HDV tape to a harddrive. And have it there for the future. Is m2t the best format to use in future?

Yes. See the first sentence of my earlier reply.

Can Premiere CS3 do scene split or shall i use HDVSplit 0,77?
I remember i used HDVSplit for capture with scene detect in CS2. But in the last year i have only done Photo. But i think I used scene detect for DV/SD but not working for HDV in CS3?
What capture program is best for capture with scene detect/split?