If you are staying in a hotel, you may need to bring things like your own water bottle, cups, a cooler (depending on how nice your room is) and you may even want to bring your own towels.
Corporate Housing is different from many other forms of housing, to the point that there is a different list of things you will want to bring and concern yourself with if you are staying Corporate rather than Hotel or Unfurnished.
Laundry: you will rarely have to worry about renting a washer and dryer, or making trips to the local laundromat, when you stay in Corporate Housing. More often than not, you will be furnished with your own washer and dryer so you'll just have to make sure you've brought your favorite brand of laundry soap. Forgot it? No need to worry, there's generally a store in your area that will carry it!
Pets: more often than not, many Corporate Housing companies allow pets in the apartments for a minor fee that is generally refundable upon completion of the lease. This makes it a great deal easier to keep your pet with you when you travel, as you will not have to worry too terribly much about finding a place for them. And while you will always want to ask to be sure, rather than assuming, it is not uncommon for you to be able to keep your furry (or feathered) friend with you.
Wifi: in many hotels, you have to pay extra for the wifi code. Especially if the hotel is more upscale. However, when you stay in Corporate Housing there is no extra fee. Internet and cable packages are automatically included in most apartments, and can be custom designed to fit your needs. So if you do not want to be paying for cable when you plan to only use the internet, you do not have to.
Your clothing, laptop, phone charger, and whatever else you might want in your new abode. But really, there is not not a whole lot to worry about when you stay Corporate!