Here is the notes from “InnoDB status, architecture and new features” by Heikki Tuuri and Ken Jocobs.

• Introduction
  • Announced Plugin 1.0 for MySQL 5.1
  • fast, reliable, proven
  • fast
    • row-level locking, MVCC -> high concurrency & throughput
    • high performance CPU, memory and I/O architecture
    • efficient indexing (covering)
  • reliable
    • automatic crash recovery
    • integrated referencial integrity and transactions
    • online backup
    • well written, well tested and large user community
• New in 5.1
  • plugin 1.0 announced
  • can be usable with partitioning, row based replication
  • reduced “next-key”