Thanks to pennybuster pointing the way, and now that I’ve figured this out I thought I’d share.
First off, it’s not is_active that you want to set the default_value to ‘1’ because that attribute applies to categories not products. If you want to make categories default to active though, that’d be how to do it I suppose. So to get products’ status to default to “Enabled” you’ll want to set the default_value of the status attribute to 1 (naturally). It’s the attribute that comes right before tax_class_id.
Also, I was having issues getting the Tax Class dropdown to select “None” as the default as well, using ‘1’ as the default value. So for fun I tried setting it to ‘2’ and I found that it selected the tax class with an ID of ‘2’. Turns out there’s no tax class with an ID of ‘1’ after all! So I figured, maybe the value “None” defaults to ‘0’. Thus, I set the tax_class_id attribute to ‘0’ and it worked! So to set the default value of Tax Class to “None” you’ll want to set it’s default_value column to 0 instead of 1.
Also, in my case, the status and tax_class_id attributes had an attribute_id of 80 and 81 respectively. Thus, since the IDs of the proper attributes may vary between Magento versions and installations, instead of setting the default_value fields by attribute_id, it’s better to do it by attribute code, so that you don’t inadvertently assign the value to the wrong attribute!
Here’s some code that’s almost certainly compatible to run on your install:
/* Alternately, you could just use PHPMyAdmin to edit the values directly, via a simple web form. */
UPDATE `db_name`.`eav_attribute` SET `default_value` = '1' WHERE `eav_attribute`.`attribute_code` = 'status' LIMIT 1 ;
UPDATE `db_name`.`eav_attribute` SET `default_value` = '0' WHERE `eav_attribute`.`attribute_code` = 'tax_class_id' LIMIT 1 ;
It may also be helpful to set up defaults for your inventory quantity and stock availability attributes (e.g. In Stock instead of the default Out of Stock), because you’re creating a product to sell in most cases, and you don’t want to create it to sit around and be invisible, right? I found this thread helpful for setting up those defaults, which are handled in a different DB table: http://www.magentocommerce.com/boards/viewthread/11001/