Hmm..
Apparently it is not possible, the manifest specifies this :
https://android.googlesource.com/platform/packages/apps/Browser/+/ics-mr0/AndroidManifest.xml
<!-- Accept inbound NFC URLs at a low priority -->
<intent-filter android:priority="-101">
<action android:name="android.nfc.action.NDEF_DISCOVERED" />
<category android:name="android.intent.category.DEFAULT" />
<data android:scheme="http" />
<data android:scheme="https" />
</intent-filter>
That's so restrictive. No wonder why QR codes win over NFC.
Please, vote for my feature request if you think so too !