This is by no means an exhaustive list. Plenty of cooking and recipe websites have sections for regional cuisines that aren't difficult to find, but I sought for original blogs in English. There are plenty of regional cuisine cookbooks as well, so do not feel limited to the internet (is that a limitation? I wonder...)
Hungarian
The Hungarian Girl is a travel/food guide as well as an excellent source for recipes and a Twitter friend!Hungarian Food Guide is a good resource as well.
Polish
So Much Begins With A Meal - Polish cuisine, complete with recipes.Polish Food and Recipes isn't winning any design awards, but it's solid.
Polish Plate
Coffee and Vanilla
Anula's Kitchen is definitely original and features a lot of Polish food.
Czech/Slovak
My Favorite Czech Recipes may not be the prettiest looking, but it delivers on content.Czechmate Diary is not strictly about food, but she has a label for all Czech/Slovak recipes.
Slovak Cooking is entirely devoted to food and found through this Pinterest board, which has a good selection.
Slovenian
Slovenian Roots Quest is not a strict food blog, but the link takes you to a list of recipes, which can be found on the blog by using the search bar.Culinary Slovenia (the English sister site for Kulinarika) has a wealth of information.
Romanian
Moments Sweet and Fragrant (Clipe dulci si parfumate) was among the 36 blogs I found listed here, though mostly in Romanian.In Bucatarie Cu Tata (In the Kitchen With Dad) has a decent selection as well, though I'm not sure if it's strictly regional.
Croatian
Bite My Cake is a bilingual food blog that is adorable (and she writes the column for Honest Cooking below).Essence of Dubrovnik is a mixture of food documentation and recipes, which gives a fun voyeuristic vibe.
T and T Kitchen Atelier is in Croatian, but the translation function works great.
Croatian-English Parallel Corpus of Recipes is an interesting blog since it's half folklore project, half recipes.
Old Time Cooking Recipes does have a decent Croatian cuisine tag.
Bosnian
I didn't find much, sadly. I found a few featuring Bosnian recipes, but nothing close to some treasure troves I found elsewhere: Gourmandize and Travel by StoveSerb
I Love Serbian Food is pretty explicit in its content. Serbian food and lots of love.Food for Thought is bilingual and has a great breadth of content
Montenegrin
Most of the blogs I found were putting Serbian and Montenegrin together.Macedonian
Sitnoseckano grew into its own website, from its humble blog beginnings.My Macedonian Kitchen is a lifestyle/cooking blog when the author was living in Macedonia.
Macedonian Food, Cuisine and Recipes is straight with only recipes.
Albanian
I didn't forget this country, but food blogs seem to have done so.Bulgarian
Angel Love's Cooking is already bilingual, but it does provide a translating option, which I love.Ukrainian
Natasha's Kitchen is beautiful and the food looks amazing.Claudia's Cookbook has a delightful selection to drool over as well.
Moldovan
Health Cooking is a mixture, but heavily features native cuisine.Lithuanian
Surfing the World Cuisine - an interesting mix of Turkish and Lithuanian cuisineLatvian
Cooking In Latvia is a work in progress, but it looks promising as a resource.Estonian
Nami Nami is not strictly an Estonian cuisine blog, but she does have 175 entries for Estonian food, found easily with the post label. (Side note: doesn't this kringel look fantastic? Contrary to what the website says, the blog is Romanian and doesn't feature much Estonian food)Belarusian
My Native Belarus doesn't give much, but most blogs were light on the cuisine.A Global Garnish featured very few and Our Food Recipes provides some links.
Armenian
The Armenian KitchenAzeri
AZ Cookbook: Food from Azerbaijan and Beyond - a mix of everything, but more focused on Azeri foodGeorgian
Delicious Georgian CuisineRussian
RusCuisine.com: Authentic Russian Recipes, Cuisine, and Cooking - possibly most excited about this because I've been wanting to make zakuskiAll-Stars aka Featured Almost Everybody
Food Perestroika: Adventures in Eastern Bloc Cuisine - probably going to be a favorite for any pan-CEE food loversPalachinka covers Bosnian, Bulgarian, Croatian, Estonian, Hungarian, Macedonian, Serbian, and Slovak, though not necessarily in large quantities.
About.com does not have a bad page for eastern European cuisine, so I suggest checking that out as well.