Web Log Analysis e.g. Browser Stats, Advanced Queries
This would include useful transformations such as Browser, OS, etc. Think old-school AwStats.
Also I'd like to be able to do more advanced queries on the log data. For example, group by username and date and count rows. Think old-school LogParser.
This would primarily be a feature of "Errors and Logs". There may be flow-on benefits into APM too though.
Currently, I have to also push my web logs into others products to get these stats out and I'd love to ditch that and save myself lots of time!