I once saw a nice solution which would prompt you with the results of new/missing, but i could not find it again…

So for a quick solution i added 2 new aliases:
1: add all new files
2: remove all missing files

#~/.bashrc
alias svn_add_new="svn st | egrep '^\?[ ]+' | sed -e 's|^?[ ]*||' | xargs -i svn add '{}'"
alias svn_rm_missing="svn st | egrep '^\![ ]+' | sed -e 's|^![ ]*||' | xargs -i svn rm '{}'"

Happy committing!

source and also useful: svnapply

another goodie: alias remove_svn_folders=”find -name ‘.svn’ -type d -print | xargs rm -rf {}”