Now that I have looked over most of the Tentative List for Oceania, some general trends seem to stand out:
Coral Reefs: Many Pacific nations seem to want to get in on this natural wonder, proposing untouched and/or richly biodiverse coral ecosystems. To be fair, some of these tentative sites are in the Coral Triangle, but I don't know how much room there is on the list for incredible coral reefs. Out of the ones I looked through, I was most interested in the nominations for the Marovo-Tetepare Complex (Solomon Islands) and the Marine Protected Areas of American Samoa (USA).
Avian Hotspots: Not surprisingly, there is a high degree of endemism for fauna in Oceania, particularly when it comes to bird life. This continent of islands is also very important for migratory seabirds. At least a dozen tentative sites include references to their avian excellence, but most of the sites also include references to other important natural and cultural features, which may be more of an overall factor for getting them inscribed. Sites like New Zealand's Kermadec Islands and Marine reserve or Whakarua Moutere (North East Islands) might have opportunities for inscription if they were to improve their packages.
Mixed Sites: Perhaps pulling from the success of Papahânaumokuâkea (USA) and Rock Islands Southern Lagoon (Palau), several countries have proposed mixed sites to take advantage of the natural wonders and biodiversity as well as the cultures that live in and rely on these environments. Some of the proposed tentative sites, such as Les Iles Marquises (France) and Fagaloa Bay-Uafato Tiavea Conservation Zone (Samoa), seem promising, but others, like the Northern Marshall Islands Atolls (Marshall Islands), need more work.
Looking over the list, the unique nominations that interest me most for cultural sites are the Yapese Disk Money Regional Sites (Micronesia and Palau) and the Nowon and Votwos of Ureparapara (Vanuatu). For the natural sites, I'm intrigued by Yaduataba Crested Iguana Sanctuary (Fiji) and Marianas Trench Marine National Monument (USA).
I'd also love to see some more transnational sites put forward to highlight the region's rich heritage, from the Lapita culture to more recent Polynesian cultures, sailing across the Pacific.