Simple things should be made simple. In DBI, to get a row of data using a primary key for the bind variable, I need to create a statement handler, bind a parameter, execute, and return some structure. 4 lines of code I use everywhere, but I wind up keeping DBI libs so that I don't have to do that all the time. Pains me to see people write those 4 lines everywhere.
A consistent interface framework for CRUD'ing my data. SQL is nice, but frankly, it's the pits going from a 4 table query, into a set of objects. ORMs do that silliness nicely.
Requesting data also always requires SQL. Wouldn't it be nice if I can use a set of the ANSI SQL language and have it translated to my DB's version of SQL. I'm tired of converting sql statements from one db's SQL into another. Don't even start me on openning a connection for rollback-able transactions.
Consistency in the low-level operations. I don't trust people's driver level libraries to be remotely consistent. I want to setup, breakdown and have queries adhere to timeouts in a consistent fashion. Setting up evals with alarms is something people should not have to think about.
Cross DB support. Ever need to join two tables aross do different databases? It's the pits.