As most of you know, two recensions of the Ṛgveda in addition to the long standard Śākala/Śākalya recension have become available in the last several years. They are:
Āśvalāyana-Saṃhitā of the Ṛgveda, ed. B. B. Chaubey, 2 vols., New Delhi: Indira Gandhi National Centre for the Arts, 2009.
The Ṛgveda Saṃhitā of Śāṃkhāyana-Śākhā, ed. Amal Dhari Singh Gautam, 4 vols., Ujjain: Maharshi Sandipani Rashtriya Veda Vidya Pratishthan, 2012-2013.
I would be very interested in comments from the Vedic scholars here about the significance of having two additional recensions of the Ṛgveda. In particular, I was earlier informed that an 1897 book in Danish by Hans Vodskov, Rig-veda og Edda, has a chapter attempting to demonstrate that the Ṛgveda we have shows a very late style. My informant noted that Vodskov's views about the late style of the Śākala recension have not been adopted by Vedic scholars. Now that we have two additional recensions, almost identical to the Śākala recension, I assume that this would be significant evidence for an early, unchanged style.