I have "a few" projects I'm working on / intending to work on in the near future.

Folios is the big one.  This has sub-projects:
MM:
 * Get large folio support in (5.18)
 * Convert GUP to folios (5.18)
 * Convert page_vma_mapped to folios
 * Convert rmap to folios (depends on page_vma_mapped)
 * Convert vmscan to folios (depends on rmap)
 * Move split_huge_page() to non-THP code
 * Get rid of all thp_size(), thp_order() and thp_nr_pages() calls (probably?)
FS:
 * Adapt NFS to use large folios
 * Adapt btrfs to use large folios
 * Adapt CIFS to use large folios

Tangential to folios:
 * Phyr
 * Slab (Vlastimil took this over.  merged 5.17)
 * net pool as its own type
 * pt pages as its own type
 * zspage as its own type
 * Can we make mapcount more sensible or disappear entirely?

Unrelated to folios:
 * Maple Tree (Liam is doing most of the work)
 * Shrinking struct mutex (Vishal has taken this on)
 * Removing PG_private
 * Synchronous ->readpage
 * Broadcast readpage errors to all waiters
 * Implement ->readahead for squashfs (Hsin-Yi)
 * ImprovedReadaheadAlgorithm
 * Make the last argument to read_mapping_page() / read_mapping_folio() a struct file ptr
 * Slab Sevenths (Bill is attacking this one)
 * NUMA-aware zero page (Bill is working on this one too)
 * NUMA text pages in the page cache (Linus seems sceptical)
 * Usercopy (5.18.  With Kees)
   * If we check ->mapping for order-0 pages, is that a sure sign of individual allocation?
 * Big Buckets (or integrate with Maple Tree)
 * Readahead for compressed filesystems in general