This isn't necessary for systems that already have H.264 decoders provided by the OS, but it's useful for platforms like Windows XP (which still accounts for 20-30% of web usage) that don't have built-in H.264 decoders.
Firefox already uses cryptographic signatures to verify other code that it downloads (including updates to Firefox itself); it could do the same for the Cisco H.624 decoder.
Windows XP users already need to download a third-party binary plugin (e.g. Flash) to play H.264 videos in Firefox. Cisco's code has the advantage that it is open source and could be signed and distributed by Mozilla.
Correcting myself: it looks like Mozilla can't distribute the binary itself (while still benefiting from Cisco's end user licensing), though it could still publish its own signature for verification.
Firefox already uses cryptographic signatures to verify other code that it downloads (including updates to Firefox itself); it could do the same for the Cisco H.624 decoder.
Windows XP users already need to download a third-party binary plugin (e.g. Flash) to play H.264 videos in Firefox. Cisco's code has the advantage that it is open source and could be signed and distributed by Mozilla.