You will have to spend some time upgrading, depending on wchich and how many plugins you are using. Usually the bottleneck comes if you have too many plugins, and one or two of them don't work with the upgrade, then you need to get into coding.

If you are expert in php, then no problem. If you have no knowledge of coding, its best, to simply stay with 1.6.1 until the plugins are updated, and then switch to 1.7.

Estimate, is that 1.7 is going to be released in December 09.

Regards,
Uddhava dasa