Drupal in my opinion is as powerful as WordPress and even more powerful. However for someone migrating from wordpress to Drupal may not know of all the modules or add-ons to install. This is an attempt to address that audience. For any blog I believe the following modules are good to start with.
WYSIWYG Editor (API) — This is will give your drupal site WYSIWYG editor. However this is just the base module. Along with this you will have to install any one popular WYSIWYG editor like FCKEditor, TinyMCE and so on. The instructions are easy to follow for install.
Webform – In case you want to create custom forms for some reason, this module will do the job. You can even email the forms when filled.
Google Analytics – Check the statistics via google analytics module. This is optional. You can choose to directly embed the analytics code.
Backup & Migrate — Greatly eases the pain of moving changes from your local development environment to the live server and vice versa.
Voting API +Fivestar – You can provide the voting ability to your users. Voting API is the must, however there are other modules that you can use with Voting API, if you don’t want to use Fivestar. However its good to start with. You can then provide your top rated content block to your users.
Notifications – Provides the ability to send emails when someone comments, or replies to a comment. Very important module to get visitors back on your site .
Captcha + Recaptcha – Standard Antispam system. You can use it for registration page, comments page etc
Taxonomy Menu – This will automatically generate menu item from categories. Very useful if you want to create menu out of your blog categories, use Nice Menus along with this module to show your categories as drop down menus.
Trackback- Adds TrackBack support to Drupal. Sending and retrieval of TrackBacks are supported either using POST or GET.
Comments moderation: Comment spam is frustrating for adminstrators, this module can help to reduce the overhead of moderation. You are pretty much back in control again and you are no longer at the mercy of whoever enjoys to abuse your freedom of speech for their own profit.
Collaboration and Social Networking
AddToAny’s Share/Bookmark widget helps readers share, bookmark, and email your pages and stories using any service, such as Facebook, Twitter, Delicious, Digg, and over 100 more sharing and social bookmarking sites. Services are updated automatically. The button comes with AddToAny’s customizable Smart Menu, which places the services visitors use at the top of the menu, based on each visitor’s browsing and sharing history.
The Comment NotifyModule improves your site by allowing both authenticated & anonymous users to get email notifications about comments on threads to which they’ve commented.
The Facebook Sharemodule enables Drupal site administrators to add a Facebook Share button to selected content type nodes in their website(s).
SEO and Content
Pathauto – I use this module a lot, on all my sites. This module allows you to automatically or manually set the URL alias for any node or page. You can also use tokens to set the URLs like author’s username, or the content’s title. So if you set up a blog entry to use tokens like [author-name]/[title] then a blog entry by “James” titled “Drupal 7” will be rewritten mydrupal.com/James/drupal7
Printer, email, and PDF Versions – I think its good to provide this feature in your blog, since many people would prefer to print and read later. You can also send contents via email.
NodeWords – The name is misleading, but this module will help you set meta tags for each page. When writing a new blog post you can mention on the same page what are the meta tags you want to use. Very effective for SEO. A killer feature in drupal.
Page Title – Again this module will help you set an alternative title for the tags and for the tags on a node.
Global Redirect – I think this is almost a must have module. Duplicate content will get you low SERPS . For Eg: http://mydrupal.com/node/1 can no longer be seen. This avoids any duplicate content and your site will rank better.
Video and Image Handling
How do you insert an image into your page? How do you upload image files?. See below for Image module and its alternatives.
For simple image handling like wordpress , use http://drupal.org/project/imagepicker. This does not create the node for image. Another module http://drupal.org/project/imagecreates a node per image and includes a gallery option that works with taxonomy terms for organization. A good choice if you are not using a separate gallery module.
Documentation: http://drupal.org/handbook/modules/image. This is now a basic functionality in Drupal 7.
For full documentation on Image Handling check this page. http://drupal.org/node/528074.
Likewise check this page for your options on Video and flash handling http://drupal.org/node/645768
For advanced users (bloggers)
As you would have noticed all the modules above are very simple. Does not use views or CCK. Once you start using Views, CCK you can do loads of other things in drupal which you would have never imagined in your wordpress or other blogging systems. Check some of the posts related to blogs
Creating similar posts or related posts block
Create avatar blocks of new and currently online users
Create a manageable blogroll with Views
Paypal donation using CCK
Friendlistis a foundation needed to build a social network-oriented website with Drupal 6
The Application Toolbarmodule, abbreviated Appbar, provides a toolbar that stays at the bottom of the window (like Facebook’s Application Bar). The Appbar can hold blocks on the left, and an “alert” dialog on the right. The alert dialog refreshes automatically via AJAX at an administrator-defined interval, and shows updates from the site that are relevant to the current user. Blocks can be displayed either inline on the toolbar or in a dialog that appears over the bar when the subject of the block is clicked.