One possibility to synchronize the contacts is to use a google mail account. This works because GMail is able to import contacts exported by outlook as comma separated file. When using the Nexus Phone one typically uses a GMail account anyway, so this is a natural way to do it.
Follow these steps:
Thats it, more or less. As the Google Nexus will synchronize all mails and contacts with your google account automatically (of course it has to be set up accordingly) the contacts will appear at the phone after a short time. Additionally it shall be mentioned that Google has a great tool to find duplicate contact-entries or to merge contacts.