Airport Extreme wired to Time Capsule?

After the hard disk on my wifes MacBook having failed fatally last week (yes, we had a two-week old SuperDuper backup, but it is annoying in any case) I am now considering to get a Time Capsule.

I already have an Airport Extreme (a couple of years old). Would it be straightforward to just wire the Airport to the Time Capsule (Time Capsule out LAN, Airport in where modem goes in today) and use ot for setting up two wireless networks (one being g and the other n)? Will Airport Utility pick up both? Any issues with the built-in Firewall? Anything else to consider? Will it work?

the new time capsule has a built in A/B/G/N router, you can use the older Extreme as a bridge or expander, for the network. Airport Utility will need to be upgraded, the new software comes with the device, then it will download a few more updates.

you wont have any issues