If they add a sewing pack and a fashion career I hope and wish they could add something that works like the Spore monster creator but for clothes, where they give us different top shapes, with different sleeve shapes, with different bottom shapes and we can mix and match and put them together to create a piece of clothing. We should also be able to select a pattern or a colour and add different extras like a pocket outline or a necklace or buttons, ribbons, etc.
As for other things I'd like my sims to sew is bedsheets. I am so tired of the bedsheets we have in game, it makes it difficult to choose a bed when decorating a bedroom, you either have to choose between bedsheet colour or bed frame colour, if the bed frame colour matches the room, you can be assured the bedsheets will be some garish clashing colour.
Also, would be nice to have some table clothes and quilts. Quilts could work like the bear rug.